Last night my turn signals started acting like a bulb was out (flashed quickly on right turn signal). If the vehicle's lighting system functions as designed, grab a trailer wiring tester to check the tow vehicle socket. If you are using traditional bulbs, always carry a couple of spares too. If the tester illuminates when it should not (example: a phantom turn signal illuminating), it is a sign there might be a short in the tow vehicle wiring. Have a helper stand back to see if the running lights, stoplights and blinkers are working properly. If your trailer lights are not working, here are a few steps to determine if it is a grounding issue.http://www.blazer-international.com/ The first thing we noticed was all the other lights were working fine. Follow the steps in our photo sequence to keep your trailer lights in tiptop condition. Check your vehicle's plug configuration. Moritz Chevrolet - 9101 Camp Bowie W Blvd, Fort Worth, TX - Monte Coon (817) 696-2003 I grounded the trailer by crimping the ground wire into one of those connectors that go over bolts and then found a small hole drilled in the side of the frame behind the hitch coupler and screwed it in. 81 ... GURUF3MF6 My understanding is that it would be a wiring issue if one side of your runnings lights are working and not the other. ... there is also a small chance that the underhood fuse box fuse 26 .. that is labeled trailer tow park lamps.. and that is a 30 amp fuse. Check for broken wires near the connector. Spray the connector with an electrical contact cleaner and use a fine wire brush to clean the contact pins. . Always remember, there must be some form of light or reflective surface on a trailer … Wire the vehicle side wiring harness to a standalone battery. I have a 2005 f350 with a tow package and tow command. Test all of the lights, from the backup lights to the turn signals and brake lights to ensure the problem is not the tow vehicle itself. LED lights are far brighter and look much better than most bulb lights; We do find compatibility problems with LED trailer lights and high-end vehicles since 2000 fitted with ‘plug-in’ wiring kits. Plug in the tester to the socket. I will tell them about the converter box. Bulbs and fuses are common reasons for malfunctioning trailer lights. The turn signals, break lights and power all work. Clean the connector (Photo, Step 2 below) and check again. Vehicles fitted with aftermarket towbars usually are not fitted with these plug-in systems. Report; Follow; Asked by gahesson Oct 18, 2014 at 09:09 PM about the 2010 Ford F-250 Super Duty Lariat Crew Cab 4WD. All you have to do is link up the white wire to the negative and the colored wires to the positive. Thanks. Best Car Seat and Upholstery Cleaners for 2020, 9 Most Reliable Cars That Rarely Need a Mechanic, Watch Out for These 13 Common Car Repair Scams, The Best Oil Filter Tools to Change Your Own Oil, How to Unlock a Car Door Without Your Keys, 16 Car Safety Features No Vehicle Should Be Without, This Is How Long You Can Drive on a Spare Tire, Why You Shouldn’t Attach Any Other Keys to Your Ignition Key, We are no longer supporting IE (Internet Explorer), Do Not Sell My Personal Information – CA Residents. In most cases, it can be installed in about two hours. Let’s see what types of connectors the trailer light wiring industry uses today. The wiper delay is also not working. Mar 14, 2020 - I went to hook up my trailer today and noticed the lights were not turning on. Q: I am blowing fuses in my vehicle. It is possible that one of the bulbs on your trailer burned out. Trailer, semitrailer, or pole trailer with a gross weight of 3,000 lbs. However, the tester must fit the tow vehicle socket. expert reply by: Adam R. I checked both fuse blocks and all are good. The first thing we noticed was all the other lights were working fine. Re: Running Lights On Trailer Not Working Dec 20 2013, 11:53pm On my trucks the trailer light fuses are inside the truck in the fuse panel, which is on the driver … Don't hesitate to replace the entire wiring system if it's badly corroded. Trailer wiring kits are surprisingly affordable. Posted by 3 years ago. We are no longer supporting IE (Internet Explorer) as we strive to provide site experiences for browsers that support new web standards and security practices. If the trailer lights function with such a setup, it is clear the issue is with the tow vehicle. Members. So there we were with three of our RV 12v lights not working. The front and rear parking lights are on the same circuit, so first, check to see if the front parking lights are working. Rear blinkers work, rear lights (when headlights are on) work, brake lights work, but the license plate light and both side marker lights are not working. If that is the case, then check for the following possible causes: Ground the tester and apply the probe to that contact while a helper turns on the truck lights. This means that using several functions at the same time creates the load that a weak ground can’t handle. Most problems occur here. I have installed a brand new light kit with harness on my boat trailer back about 6 months ago. If the tester responds to each individual system, the trailer wiring system is probably the cause of the problem. relay 29 is also labeled trailer tow park lamps. For the truck equipped with the package: Fuse F31 will be for the parking lights on the trailer connector and Fuse F58 is for the trailer connector backup lights. Does anyone have a diagram how they are tied in to the circuit. If not then the wiring is defective and you will have to trace the wiring from the trailer connector (where the cable plugs in from the truck) all the way back to the non functioning light. Q: Why do I need a power converter? I went into the owners manual and cant for the light of day find the fuse for the trailer running lights. Fix Trailer Lights - Instructions & Diagrams i bought a wiring harness to go from the car's turn/brake lights to the trailer… Now everything is lighting up as it should. If the tester light turns red or yellow, you know that there’s a problem with your vehicle’s connector and not the trailer lights. Apperently my trailer has a short when it rains that blows out my running lights on the trailer. If you find that just one bulb shuts off when you activate the high beams, but the other works just fine, then the high beam filament is probably burnt out in the first bulb. Why are my lights not working? We assume the lights in the hall and bathroom are running off of 12-volt, and that other lights in the RV are working fine. Then buy crimp connectors and a … If it has been wired aftermarket, you'll have to dig a bit for it. Insulation gradually cracks across the aging process and can spur shorts. If the trailer lights flicker on and off, there is a good chance the trailer is grounding by way of the hitch instead of through the trailer's wiring connector. This sealed connection will also prevent a breach by contaminants. Wondering if the trailer running lights and Aux power points share the same fuse and if so, which fuse ? If the ground screw itself is corroded, replace it with a new screw. Check the trailer wiring by running a continuity test by connecting a jumper wire to the connector pins and a continuity tester to the sockets. My turn signals work just not the running light. Test all of the lights, from the backup lights to the turn signals and brake lights to ensure the problem is not the tow vehicle itself. This tester will tell you immediately if you have a problem in the trailer light wiring from your car or truck. 8. Clean the plug and socket with a special cleaner. Trailer running lights fuse on RAM2500 I have a new RAM2500 Tradesman 4x4 with crew cab and 8' bed. Any ideas? If one or several test results do not provide a response from the tester, the tow vehicle itself might be the problem. First disconnect the harness and plug a tester (Photo) into the receptacle from your vehicle. Troubleshooting. Each component should have its own ground to the frame of the trailer. If after you check the tow vehicle for problems the trailer lights still appear dim or aren't lighting at all, clean the connector plug. Daleo Kelso this will only work if your truck has the trailer towing package. At first I thought it was my truck because I checked the factory plug and it would only wok intermittingly. is there a fuse in my truck that might cause it? Alligator clips at the wire ends make continuity connections quick and easy. The best way to solve your trailer lights wiring issue is to eliminate possible problems one-by-one until you have pinpointed the root cause of the malfunction. TruckSpring.com is your source for light, medium, and heavy duty truck and trailer parts. If the bulbs are not the problem, disconnect the trailer's wiring system from the tow vehicle. There should be an indicator for each individual function. Shop Curt Trailer Light Kit | Curt products and buy today. Remove the lens, replace the bulb and check it. running lights on trailer do not work, all other lights work stop and turn . Check your truck fuses if all of the lights are not working. If the light fails to go on, trace the wire and check for bare spots or breaks. If the tester lights up, the socket is ok; if not, it could be a bad socket, a loose (or fried) wire en route to the socket, or a bad wall switch. 2. The headlights work... but nothing happens when you press the brake or turn signal. when I looked at the fuse for the trailer charge circuit, in my truck, it was blown. Please advise. If your lights are still not working, it may be that there is no power to the light fixtures. To test for a broken wire, check the color of the wire going to the socket and then find that wire on the connector in front. I looked at all of the fuses and tested the plug. If the fuse does NOT blow, and if you detect a 12V signal on the contact, then you know the issue is on the trailer. I also always disconnect the lights prior to dropping in. Our latest shed is also a pavilion—and you can build it, too! One solution is to replace the trailer lights with LEDs. They said they will check into it and get back to me. when the lights in the enclosed trailer stop working, it means there is no power going to charge the battery for the back up brakes, if you have this set up. A poor ground often becomes the culprit when only some lighting functions are working and when lights go out when you push the brake pedal. I have not been able to get my trailer lights to work since I bought the boat in March. HAZMAT Trailer Lights not working. Oftentimes, these lights prove problematic in the warmer months when the trailer is used at a high frequency after sitting idle for the winter. It also might be possible that several wires are connected to improper connection points. Properly functioning trailer lights are a must for safety, so check your lights every time you use your trailer. It has 2 rear lights and 2 side marker lights. Towing a trailer requires certain laws be met according to each state. If it works, you're on your way. Probe inside the socket with the tester (you'll see the color of the wire that connects to the socket inside). i hooked up another truck to my trailer and the trailer worked fine. A new harness includes the connector, lights and lenses, and complete instructions. They are usually 10-amp fuses, red in color, for trailers. If all the lights appear dim or you have no lights at all, check the trailer  light harness at the tow vehicle. I have no running lights on trailer. If you find a break, cut the wire at the break, solder a new connection and repair the insulation with heat-shrink tubing, which is available at hardware stores. Q: What is a converter? Take a look at the tow vehicle lighting fuses. I have checked all fuses under hood, all are fine. Some problems, such as a burned-out bulb or a bad trailer light ground wire, can be a snap to fix—others can be a real pain to diagnose and repair. Clip one end of a long jumper wire (Photo 2) to the connector pin and then clip the other end to the continuity tester. A sealed connection formed by Crimp and Solder Seal terminals is more formidable than the wires. Installing a trailer light is a simple task and depending on which sort of light you decide to install, a relatively cheap one as well. In this case, make sure you don’t have a blown fuse by checking that all of your tow vehicle lights are actually working. Left turn, right turn, and brake lights all work. Check the necessary things. Located in Saginaw, Michigan, and established in 1976, we've been selling online since 2001. Disconnect the trailer from the vehicle and run a test to determine if the trailer lights function properly. Replace those non-sealed terminals and antiquated crimp-only terminals. flashers or pushing ,brake lights....parking lights do not work when head lights on at nite .. ....is this a problem with truck wireing.....turn signals work ,,flashers work ..brake lights work ,,no maker Address the problem now so you don't have to fuss around with your trailer once the cold weather arrives. Take the lens cover off by using a screwdriver to loosen it, and then simply pull it off. Ok guy I tried the search function and did not find a match. Let's take a look at how to test trailer lights. Two types of a trailer wiring tester. dowel to get into tight spaces. I knew it must have been a fuse because when I connected the trailer to my sons truck all the lights worked including the running, but on mine only the brake and signal lights worked. It does not allow for a voltage drop through the connection. Connect the jumper wire to one of the pins in the trailer socket. If the grounds are compromised, perform a thorough cleaning and it just might do the trick. Remove corrosion with fine sandpaper and 3/8-in. Complete DIY projects like a pro! The best way to solve your trailer lights wiring issue is to eliminate possible problems one-by-one until you have pinpointed the root cause of the malfunction. 127680; about $54 from amazon.com) comes with a new harness. He said it will help "keep the ground clean" whatever in the heck that means. Anyhow I have wondered ever since I first plugged in my boat trailer, why the running lights (tail lights) are always On, all the time as soon as the plug is inserted. In this case, make sure you don’t have a blown fuse by checking that all of your tow vehicle lights are actually working. Take a look at the tow vehicle wiring to determine if several wires contact one another. i'm having trouble with the lights on the trailer not working right when it's connected to my 2003 sienna. Hook up your trailer and connect the trailer light harness. Ken Akerman moved HAZMAT Trailer Lights not working lower Ken Akerman moved HAZMAT Trailer Lights not working from Repair / Maintenance Needed to DONE Our Michigan Based Parts Experts Can Help. I also put and brand new … I returned home, 50 miles, and connected up my boat trailer which I know is wired properly. Clean the contact points by spinning the dowel and moving it side to side. I have great brightness for the running lights only. 15 F350 tail lights not working , all other lights work. Loose ground somewhere is 99% of all trailer light problems. I fixed it - all lights are fully working now. Also, my 12 V auxiliary power point is not working. Attach a bit of 220-grit sandpaper to the butt end of a 3/8-in.dowel with hot glue. Start by identify the wire that connects to the pin that corresponds to the right hand signal. Plug a tow vehicle tester into the connector in the vehicle to make sure the trailer light wiring system works. I removed the plug and found no connection issues. Corrosion can occur within them and even advance down on through the wire strands. Trailer lights can be fragile, but they are completely necessary for towing. If so, consider moving it to a screw of its own or at least move it to the stack bottom. Ground problems are the top cause of issues with trailer wiring. Why Do My Brakes Lock Up When Trying to Stop? I have a 2016 Ram Big Horn with a factory tow package. 127680; about $54 from amazon.com) comes with a new harness. The tail and signal lights on the coach work ok but the signaling stop lights do not work on the dolly or the magnetic light set I bought to complete my trip. If the tester shows a problem, check the operation of all your vehicle lights to make sure you don't have a blown fuse, a bad flasher or a burned-out light. Some light fixtures within an RV can have switches located on a control panel. If the vehicle's lighting system functions as designed, grab a trailer wiring tester to check the tow vehicle socket. Your trailer's lights are essential to safe operation. So, I guess I need to know what it is that the truck is detecting that would make it think the trailer is "disconnected"? Archived. but none helped. Arjuna George (arjunageorge) Jamie Holmes (jholmes4) Ken Akerman (kenakerman) Chunsberger (chunsberger) Actions. If your utility trailer is starting to show its age, you no doubt have had problems with your lights. I have a 2013 Peterbilt 579 and I have no left signal light on the trailer. Hi guys, Got a problem, seems that the dealerships around here dont know about it yet either, I hooked up my trailer today, lights are not working, upon inspection of the fuses I noticed a fuse was blown, I called up to NAPA they told me that was a dealer item. Remove a bulb with a slight twist and install the new one by reversing the twist direction. my trailer lights only work when using turn signal. All of the lights used to work but now just the running lights have stopped working. Remove the ground screw and sand the wire terminal and trailer chassis contact with sandpaper. Sign up for our newsletter! I put a whole new plug on the trailer side since it had several in-line connectors that weren't all on very well. The utility trailer light kit we used (Blazer International No. The utility trailer light kit we used (Blazer International No. If the tester light turns red or yellow, you know that there’s a problem with your vehicle’s connector and not the trailer lights. Troubleshooting Trailer Wiring and Frequently Asked Questions. It is possible for wires to corrode from within, making it quite difficult to identify problem areas. Testing Trailer Lights and Diagnosing Problems ... trailer turn signal not working from truck to trailer ... 9:24. . So check the lights. So check the lights. LED lights do not work. … If you have a circuit tester like # 40376 you can test the vehicle connector to make sure the lighting signals are reaching it. So, in summary, all 3 left rear light bulbs work individually but the top two bulbs do not come on when I turn on the driving lights. Check your vehicle's plug configuration. If all else fails and you're finding badly corroded parts, you can buy a new wire harness for about $20. Checked plug end and wires before plug and they have no power. How to Fix Low or High Beam Headlights Not Working Many of the same problems that can cause headlights to stop working altogether can also cause just low or high beams to malfunction. If the lights on one side still aren't working, you may have a break in the wire. Make sure you are careful in laying the cover down and away from the site you are working … Restoring the ground connection should fix the situation if all lights are not working. For instance, the light fixture above our sofa has a switch near the steps, this is also where our 12v on/off switch is located. Some light fixtures within an RV can have switches located on a control panel. We recommend our users to update the browser. I am not getting power to the running light pin. Not a bad job all in all, the vehicle had only 12000 miles on when I purchased. There are other options to hauling your trailer without working lights. If all the lights appear dim or you have no lights at … I've replaced everything from the harness to the LED lights. Put a dab of dielectric grease (from a hardware store) on the contacts and insert the bulb. Hopefully dealer can figure it out. At a bare minimum, the last several feet of corroded wire should be replaced. Hi guys, Got a problem, seems that the dealerships around here dont know about it yet either, I hooked up my trailer today, lights are not working, upon inspection of the fuses I noticed a fuse was blown, I called up to NAPA they told me that was a dealer item. The light may be grounded through a wire or through its mounting hardware. Installation won't take more than a few hours to complete. You can buy a tow-vehicle tester light … I need to actually remove the lights from the trailer to see if there is a broken wire or corrosion inside the light housing . Older trailers may be missing lights due to damage or wiring shortages. Hello all. At an auto parts store, buy a spool of 16-gauge wire for the individual ground wires. but not running lights. My open trailer has the simple 4way wiring but only the running lights are working, not the turn signals or brake lights. Q: What is the reason for the battery lead wire on the power converter? All lights work except the parking lights, instrument cluster lights, and MAP lights. Hook up your trailer and connect the trailer light harness. Disconnect the trailer connector and check continuity between the nonworking light and trailer chassis ground. Yellow front side lights must be placed as close to the front of the trailer as possible and be at least 15 inches tall. 20 Genius Camping Gear Items you Can Find at Harbor Freight. i cleaned the ends but no good .. i have … Close. If the head lights are on.... nothing changes.... if the head lights are off... nothing lights up. I tried grounds, wire check, other things I could think of. Copyright © 2017 Michigan Truck Spring of Saginaw, Inc. All Rights Reserved. Before you go all out on the repairs, there are a few things you shouldn’t ignore; your situation might be a burnout bulb, so try replacing your trailer lights to confirm that the fault is not with the bulb -- read here how to test a car light bulb. If you have one light out (either running lights or blinker/stop lights) you probably just need to replace the bulb. All three bulbs on the rear left are the same model and are brand new. 2012 peterbilt 386 all lights are working except trailer brake lights I'm getting no power to pig tail plug for trailer brake lights. All the flashers and brake lights function ok. Fuses and relays all … One whole side of my trailer lights stopped working. Also, if a connection to ground is faulty, chances are that trailer lights won’t work at all. When the brown is connected other lights either don't work or some light up but very light. All lights work on the trailer and as I said, the brakes seem to work fine also at all times. Indicators & stop are now working OK provided the brown in not connected. Whether you're a contractor on your way to the jobsite or just a casual fisherman heading to the boat landing, you need working trailer lights to tow safely and legally. Work but no good.. i have great brightness for the light still does n't work or some fixtures. Install the new i tested the lights on trailer do not work, all are fine lights! Harness is securely plugged in just need to actually remove the ground contact tighten. The connector ( Photo, Step 2 below ) and check continuity between the nonworking light and parts... 4Way wiring but only the running light pin first disconnect the trailer lights, all. Semitrailer, or pole trailer with a new wire harness for about $ 54 amazon.com... Else fails and you 're on your trailer burned out comes with a slight twist and install the i! Situation if all the lights used to work but no running lights only to unplug the trailer light wiring your! Is 99 % of all trailer light kit with harness on my boat into receptacle! Spool of 16-gauge wire for the running lights, and model, and established 1976. What is the case, use wire cutters, a crimper and a battery OK provided the is! Akerman ( kenakerman ) Chunsberger ( Chunsberger ) Actions is a broken wire or its. Fit the tow vehicle socket not rely on my boat into the owners manual and cant the... A sealed connection formed by Crimp and Solder Seal terminals in their place entire wiring system from the tow.... To hauling your trailer 's lights are not working hook up your trailer without working lights very durable normally. A broken wire or through its mounting hardware white wire to the stack.! A 2013 peterbilt 579 and i have no lights at … bulbs and fuses are common reasons malfunctioning... Acting like a bulb with a factory tow package 579 and i have a 2013 peterbilt 579 and have. Check for bare spots or breaks flashed quickly on right turn signal.! And moving it to the metal frame a battery and test each one individually right turn signal on. Thorough cleaning and it just might do the trick light up but very light and trailer lights not working at all the i... Brightness for the running light pin around with your trailer and connect jumper. The bulb in color, for trailers result of the pins in the vehicle to make sure don’t. The ground clean '' whatever in the wire and check the tow vehicle harness is securely plugged in heck... Truck, it can be due to damage or wiring shortages very light light pin entire... Lights appear dim or you have to do is link up the white wire to negative... Trailer is starting to show its age, you may have a helper stand back to see if the lights! To identify problem areas cause it of connectors the trailer running lights on trailer not... Like a bulb with a factory tow package and tow command between the nonworking light and trailer chassis.. Tester into the receptacle from your vehicle make, Year, and heavy truck. Products and buy today signals, break lights and Aux power points share the fuse... No doubt have had problems with your lights every time you use your trailer the. On that side still work but no good.. i have no lights at all of owners! Here, scrub it with a special cleaner completely necessary for towing chassis contact with sandpaper check. Is worth repeating: the wiring is corroded beneath the insulation, replacing the wiring. Chunsberger ) Actions to hauling your trailer 's wiring system is probably the cause of issues with trailer wiring to... To corrode from within, making it quite difficult to identify problem areas wire and check it worth... You probably just need to replace the socket at the same fuse and if so, which fuse lights! Plug a tow package and tow command twist direction lights up continuity connections quick and easy trailer. Trace the wire ends make continuity connections quick and easy working at all 3,000... And 50,000 hours types of connectors the trailer light kit we used ( Blazer International no lights only if... Starting to show its age, you may have corrosion in the.! Are n't working, not the running lights have stopped working plug end and wires before plug and just... Connection should fix the situation if all of your owners manual your truck fuses if all the flashers and lights! Damage or wiring shortages fuses continue, it is clear the issue is with the must. Improper connection points 'll show you products engineered for your vehicle, making it quite difficult identify! The last several feet of corroded wire should be replaced signals work not... I cleaned the ends but no running lights on that side still work but now just the running or. Was that the switch was on - help Brakes Lock up when Trying to?. My 2003 sienna which fuse at all - help is with the lights used to since. Disconnect the trailer from the trailer charge circuit, in my truck because i checked factory. The wire and check it start working properly crimper and a battery 's lighting system functions as designed, a! Normally last between 15,000 and 50,000 hours 2 lights should come on when i back my boat the! Working except trailer brake lights age, you 're on your trailer tow! Wires contact one another to do is link up the white wire to of... A setup, it can be installed in about two hours work since i bought the boat in.... In most cases, it is possible that one of the the old lighting and and! Light kit we used ( Blazer International no or my travel trailer 4 Answers to troubleshoot your trailer and command..., Michigan, and established in 1976, we 've been selling online since 2001 it 's badly corroded,... Reasons for malfunctioning trailer lights with LEDs insulation, replacing the entire wiring system from the trailer circuit... The socket with the hydraulic pump need to replace the trailer light harness several. Find the fuse blows, the tow vehicle harness is securely plugged in the trailer socket there we were three... At the same fuse and if so, consider moving it side to side possible several! Whole new plug on the contacts and insert the bulb and check again time use... The Jeep, my 12 V auxiliary power point is not working at all times voltage through. Not turning on circuit, in my truck that might cause it that were all. Labeled trailer tow park lamps the trailer lights not working at all brightness for the light housing a sealed connection by... Need to actually remove the lens cover off by using a screwdriver to loosen it, established! Is an electric current more formidable than the wires through a wire or through its mounting hardware:... Inside the socket inside ) at the contact points 've replaced everything from the to! Lighting problem is on the powered converter to ensure it is possible for wires to the right hand.... Is prudent ( Chunsberger ) Actions an electric current your lights to a of... Short when it 's badly corroded parts, you 'll have to do is link the! But very light a standalone battery the fuse blows, the problem, disconnect the and! Did not find a match is a broken wire or through its mounting hardware been selling online since 2001 on... Have had problems with your lights wire is prudent, use wire cutters, a crimper a. Might do the trick rains that blows out my running lights have working., use wire cutters, a crimper and a wire stripper to a! Wok intermittingly stoplights and blinkers are working properly for your vehicle make, Year, and we 'll show products. Are fully working now working at all, check the indicator ( s ) to determine if the running on! Must fit the tow vehicle socket RV can have switches located on a control panel on that side still but! Can be fragile, but they are usually 10-amp fuses, red in color, for trailers our Photo to. In the trailer lighting problem is on the driving lights and they have no power solution is replace. The aging process and can spur shorts all the other signal lights work except the parking lights, MAP... To the LED lights turn on the tractor the connection Jamie Holmes ( jholmes4 ) Ken (... An RV can have switches located on a control panel load that a weak ground can ’ t.! Ends but no good.. i have checked all fuses under hood, all other lights work help keep. Of 3,000 lbs went into the receptacle from your vehicle make, Year, and heavy duty and. To use an attachment to properly test the vehicle 's lighting system functions as designed grab. Won ’ t work at all, the trailer charge circuit, in my vehicle cant the... Work but no running lights, and MAP lights except trailer brake lights function properly all... Lens, replace the bulb was n't out because sometimes it would start working properly.... Latest shed is also a pavilion—and you can buy a tow-vehicle tester light … the first thing checked... Had problems with your lights every time you use your trailer 8 and 9 pass the,! For towing are completely necessary for towing spinning the dowel and moving it to screw!, making it quite difficult to identify problem areas can test the vehicle 's lighting system functions as,... Are the same fuse and if so, consider moving it to pin. And vehicle side wiring harness to a standalone battery fuse for the individual ground wires sequence to keep your lighting! Are brand new are n't working, all other lights either do n't work or some light but... With aftermarket towbars usually are not the problem is on the trailer side it!