My trailer lights are acting up. The runing and tail lights work fine by themselves and the stop and turn work fine as long as my tail lights aren't on. When I have my tail lights on and use the turn signals all of the lights on the trailer flash on and off. I have 7 trailers in my daily operations and have to work on lights frequently, but this stumps me. where should I start? thanks for the help
Trailer lights acting funny
- Thread starter awbrennan
- Start date
skeeter2010
Member
Typically that is a grounding issue, just to make sure use a jumper cable and attach it to to the truck and to the trailer and see if it corrects the problem
X2^ also you can use your volt ohm meter to test for voltage on the frame,
a weak spot is the mounting point of the lights getting cruddy and not
making ground.
Had a Dakota once where the lights on one trailer worked fine on it, hooked up another trailer and lights acted up. come to find out, the ground on the truck end wasn't good enough. ran another ground from the plug on the truck directly to the frame and all was good. Had 3 of us stumped as to why one trailer would work and another would NOT. As said above, try direct grounding to the truck.
Tuck Side Plug
On my 2004 the round male plug you push your trailer plug int
n the back side of the truck hook up there is a harness to that male receptacle.That connection collects salt and road grime over the year. Unplug it and clean with a electric motor degreaser,blow dry it and you should be good. Also if problems persist there are fuses on the truck that are designated to the trailer lights such as left and right turn ect. They should be listed in your owners manual. Best of Luck.
On my 2004 the round male plug you push your trailer plug int
n the back side of the truck hook up there is a harness to that male receptacle.That connection collects salt and road grime over the year. Unplug it and clean with a electric motor degreaser,blow dry it and you should be good. Also if problems persist there are fuses on the truck that are designated to the trailer lights such as left and right turn ect. They should be listed in your owners manual. Best of Luck.Canoepaddler
New member
On my 2004 the round male plug you push your trailer plug int
I had the same problem with my Chev Silverado. Drop the spare tire and the plug will be easy to get at from the front. The ground terminal is the one that was green and corroded for me. Clean it up with sand paper or emery cloth, and then electrical spray cleaner. Before plugging it back together, coat the connections with dielectric grease. I use dielectric grease on all my trailer connections and have greatly reduced connection problems.
I put a volt ohm meter on the frame. I am getting some reading from the frame when lights are on also a on and off reading while the blinkers are on. If I have the tail lights on and I hit the brakes everything goes off as long as I have my foot on the brakes. the reading is twice as high when tail lights and turn are on. What the (*&^ is going on?
It is a ground issue.
If anyone is trying to rule out the tow vehicle electrical system; use a battery charger and energize the trailer wiring that way.
But the above is a ground issue, and unhooking the hitch is a must. Could even be a grounding issue at the bulb, or fixture, or at any part of the frame, or at the connection to tow vehicle.
X2 on the digital volt meter to find power, I find a continuity test to be my best indicater of ground issues.
If anyone is trying to rule out the tow vehicle electrical system; use a battery charger and energize the trailer wiring that way.
But the above is a ground issue, and unhooking the hitch is a must. Could even be a grounding issue at the bulb, or fixture, or at any part of the frame, or at the connection to tow vehicle.
X2 on the digital volt meter to find power, I find a continuity test to be my best indicater of ground issues.
Canoepaddler
New member
That's why those fancy little plugs with the test LED's don't work the greatest either. You can have a poor ground connection at the vehicle jack and the LED's won't indicate it because they don't draw enough current for that poor connection to stand out. I bought a couple of them, but they didn't indicate a problem that was there. The best way to use those things is - If it indicates a problem, good chance there's a problem there. If it doesn't indicate a problem, you don't know much more than when you started. If somebody really wanted to design a good plug tester, they would come up with one that used incandescent bulbs instead of LED's. That's on my "fun things to do list" when I don't have anything else to do.
Definitely unhook the trailer and us a battery charger to determine for sure if it's the trailer or tow vehicle. It's not the handiest making the connections that way, but it does work. That would be another opportunity for an invention, a little self powered 12v test box with switches for the different functions that you could plug your trailer into just like a tow vehicle.
Definitely unhook the trailer and us a battery charger to determine for sure if it's the trailer or tow vehicle. It's not the handiest making the connections that way, but it does work. That would be another opportunity for an invention, a little self powered 12v test box with switches for the different functions that you could plug your trailer into just like a tow vehicle.
If you have a newer battery charger some
will not create power unless they sense power.
If thats the case turn the truck around and cut up
that old wimpy extension cord we all have laying
around. Add some battery clips and you can test
with it, I keep a spare trailer male end plug on hand.
will not create power unless they sense power.
If thats the case turn the truck around and cut up
that old wimpy extension cord we all have laying
around. Add some battery clips and you can test
with it, I keep a spare trailer male end plug on hand.
LOL now that you have all these opinions your probably scratching your head and thinking "but what do I do" electrical problems are a super pita, you have to eliminate one step then go to another until it's fixed. A newer truck, I doubt if it's in the vehicle, hook black volt meter clamp to the frame make sure it's a good clean hook-up, take red probe with meter set for dc volts, have someone help, step on brake, use turn signals (etc) and check plug-ins in relation to what the helper is doing.
Example: put probe in left turn signal & have helper turn on left turn signal, should be 12 volts maybe alittle more but not less, atleast that would rule out the truck.
If it's a tilt trailer you might be losing ground where the trailer tilts, take a piece of braided wire like they use hooking the motor of the truck to the fire wall and hook one end to the tongue of trailer and the other to the bed. Just my 2 cents worth
Example: put probe in left turn signal & have helper turn on left turn signal, should be 12 volts maybe alittle more but not less, atleast that would rule out the truck.
If it's a tilt trailer you might be losing ground where the trailer tilts, take a piece of braided wire like they use hooking the motor of the truck to the fire wall and hook one end to the tongue of trailer and the other to the bed. Just my 2 cents worth
WWWWWeeeeeelllllllllllll. I think I would rather give birth then to go through this again. This was the problem and if any one has a tilt trailer i hope they read this. I was getting proper ground at the spot where the trailer ground wire was connected. I even have proper ground at the plug. But on a tilt trailer you are dealing with two seperate pieces of frame. thus two seperate pieces of metal. one lays on top of another and is connected by a pivot bolt. Paint and surface rust had built up so the two pieces were seperate. So I had ground at the tounge but not at the trailer frame where the lights are mounted because the rust and paint had created a seperation. this way when you run a jumper from the truck to the tounge it does not fix the problem. on normal trailers everything is welded making one piece of metal so if it is grounded at one spot it is grounded everywhere. I cleaned the metal bare in spots to make good contact and it fixed the problem but if I hit bumps sometime the lights will flicker. I never knew have fun would put me through so much ****.
Thanks for all the help.
Thanks for all the help.
how long
this is so easy to fix good wire harness have a ground that goes to the tail lite . i laugh at how long and hard some make this fix always check the grd at truck then hitch then bulb , glad you did figure this out but all those extra con. will rust for next time
this is so easy to fix good wire harness have a ground that goes to the tail lite . i laugh at how long and hard some make this fix always check the grd at truck then hitch then bulb , glad you did figure this out but all those extra con. will rust for next time