Losing my mind! trailer lights.........

[Fayetteguy]

so my trailer lights only seem to work consistently for about 2 months at a time then something happens......

Ok i apply the brake, good brake lights

With brake applied and turn on either blinker it works.....however the blinker not engaged blinks faintly as well......

With the headlights on, and no other signal i have nothing, no permanently running lights, however all above still works with the headlights on....

I am about to lose my noggin, my truck lights all work perfectly.

The past issues have been a grounding problem, but i dont know why if power is making it to light up the brake lights and blinkers then why NO running lights? I tried replacing the wiring connectors on the truck bc i had 2 spares and nothing helped.

I think i had a bad ground on the trailer but like a dumb dumb i redid that as well as some other grounds at the same time, so i dont know which one helped. i think im going to go back to my old harness and try it with the new good ground on trailer to see if all is back to normal................uhg................thump.... ..that was a brain aneurysm taking me out

-FG

[Harry]

Bad ground 99% of the time.

[Fayetteguy]

Thats what im sayin! I just cant find it, i have three ground wires, 2 come from the harness on the truck side, and one on the trailer side, i have cleaned, re-edned each wire and reconnected, then went back and moved them to all new locations and still the same issue. Hopefully going back to one of my old pieces will help some because then i will have 1 ground truck side and 1 ground trailer side, at least give me only two things to bang my head in the wall about :)

-FG

[Shakespeare]

One of the things I don't like about most trailer wiring is that each light finds its ground through the shell housing or the mounting stud to the trailer framework. Over time and especially on boat trailers, enough corrosion and oxidation occurs to affect the integrity of the ground. Not saying that this is your problem but it's something to check. You might want to unfasten each light and give a good wire brushing to wherever it makes contact for ground.

Whenever the time comes to rewire one of my trailers... I'm going with lights that have a dedicated wire coming out of them for ground and forget about this using the trailer framework for a common grounding point.

[al_e._gator]

I agree with Shake, Grounds at the light housing have caused most of my problems in the past

[Gary13]

You might try isolating the trailer from the truck and narrow it down...truck or trailer. This can easily be done using a good battery, connect the negative to a good clean spot on the trailer using a jumper cable, then run a wire from the positive post and check each individual slot on the trailer plug. They won't flash of course but if they don't light up like they should, you know where to look. It's hard to get a good connection after there has been corrosion....it may look clean but usually it isn't. If the lights work this way, remove the jumper cable from the trailer and connect it to the trailer ground wire. If problem reappears, location solved. You are on the right path, don't lose the faith *laughing*.

[lever]

I had some crazy stuff happen with my lights when I didnt have a good ground. Brake lights would work, but having my lights on, or using the turn signal made me think my trailer was possesed.

[redfish74]

Just like all the others before me GROUND GROUND. A bad one will show you a different problem ever time. Good luck .

[Fayetteguy]

ok well i now have all my lights but.............when a blinker is on with brake lights or headlights on then both signals blink, the correct blinker blinks strong and the other pne very faintly


-FG

BAHHHHHHHHHHHHHHHHHHHHHHHH

[Shakespeare]

ok well i now have all my lights but.............when a blinker is on with brake lights or headlights on then both signals blink, the correct blinker blinks strong and the other pne very faintly


-FG

BAHHHHHHHHHHHHHHHHHHHHHHHH

Is there any way you can plug your trailer lights up to another vehicle to see if you get the same results? If they work fine off another vehicle then your issue is with the blinker module on your vehicle.

[NOTHING ELSE MATTERS]

You said that you have 2 grounds coming out of the truck *006*. I don't think that is normal. When you say two grounds, do you mean two different studs from the harness ?

[Fayetteguy]

i have a plug in harness to give me a trailer hookup (my truck didnt come with it). It splices into the rear wiring harness. That piece has a ground wire, then there is an extension that connects to that and runs out of the back of the truck, and the new one of those i bought has a ground wire on it. The the trailer side has a ground wire also :) i went back to my original extension w/o a ground wire and had the same issue. I may have to look around for a buddy to check my trailer for me. i had this problem once before and it was a ground issue, so i think im just being dumb and missing it.......

I have my wires wrapped together tightly at the trailer side, just behind the plug with some......not so great splicing so im wondering if corrosion got in there....it also felt a little warm to the touch so i may have a short or something, was pulling it all apart until the gnats and squitos tried to carry me away so i stopped. Gonna clean it all up tomorrow then try again :) At least i have all my lights now! just both blink :)

-FG

[watercat]

I ran a ground wire from the ground on my plugin to every light on my trailer hooking it to each ground screw. The only time I have a ground problem now is if my truck ground would corrode. The reason your light blinks dimly is because the other light is using it for a ground thru the hot side of the lightly blinking bulb.

[Redfish]

I ran a ground wire from the ground on my plugin to every light on my trailer hooking it to each ground screw. The only time I have a ground problem now is if my truck ground would corrode. The reason your light blinks dimly is because the other light is using it for a ground thru the hot side of the lightly blinking bulb.

Hate to *deadhorse* but I agree with the Cat. If you have a bad ground, the bulb that is blinking will seek a better ground through the other bulb. Shakes post much earlier is spot on, too. If you know that your wiring coming out of the harness is right (and that can be tested with a test light or multimeter), then I would start by, as Shakes said, cleaning up all contacts, including pulling each bulb and cleaning the contacts on the bulb and on the receptacle. Do this on ALL bulbs. One bad ground will disrupt the system.

Oh, and remember. Your truck becomes PART of the system once the trailer is connected. If you have a bad ground in your truck lighting circuit, it will likely show up once you put greater load (resistance) on it. (That is, hook up trailer lights).