Damn Trailer Lights!!!

Alright who’s the trailer wiring expert?

I am taking a fishing trip this weekend so I spent lastnight trying to get my trailer lights for my boat working. Here it goes… Before starting, both trailer lights lite when my head lights of my truck were on… but thats it, no brake lights or turn signals on both trailer lights. The truck tail lights worked, but the trailer didn’t.

So I used a dremel and cleaned the plug from my truck wiring and the plug on my trailer wiring, got them nice an clean. Than I Cleaned up the ground wire to the trailer… got everything sanded down to bare metal for the ground. Than I put 2 new lights on my trailer, cause the old ones were getting kinda of rough looking on the contact points.

After all that I tested them… The passenger side trailer light every thing works- turn signal, brake light, head lights. Now for the drivers side, still the only time that side will light up is when I turn on the head lights of my truck, no brake light, no turn signal on that side only.

So now what the heck is going on?

If its a grounding issue, should I just run a single wire back to each light?

my trailer is a tilt trailer and I have heard you can loose your ground to the rear of your trailer if you just ground to the trailer tongue.

any ideas?

I am no expert, but just had some problems of my own, can I ask what type of vehicle are you pulling the trailer with? Reason I ask, is I have a Grand Cherokee and in order for trailer lights I have to have a converter (amber turn signal/red brake lights) to make trailer lights work. Some of the symptoms of my trailer lights were close to yours. It was a bad converter. Installed a new one a month ago, it caught on fire, got another new one and hooked up to find out it was bad, now I’m on #3 and it seems to work fine for now. Something to think about. Get a tester and see if you have power from the connector on your vehicle.

I have a ’95 fullsize gmc pick up.

Always be sure both ends of the ground (white wire) Have better than good connectiond. Meaning on the truck side as well as the trailer. In you case the turn signal/brake side of the bulb might be bad or you probablu have a broken turn/brake lite wire on that side. Rt. green Lt. yellow. I am going to send you a link by e-mail that is always helpful. moler02

probably doesn’t have a converter, but I would still check to see if the connector from the vehicle is working ok.

Go towww.etrailer.com/fag/wiring.asp I’m not smart enough to put it on here. moler02

I had the same problem, and after I re-wired the whole trailer and still didn’t work, I finally checked the fuses. There is a fuse for the trailer lights, and one for each side signal. If you haven’t check that.

Hey Burk,
Trailer lights can be so nasty.
Drive the vehicle into a place that rents trailers and ask them what it will cost to get them hooked up. It should be worth the cost. Good luck.
Swede

I checked all my fuses and I didn’t find any blown.

I am going to try to hook my truck up to my buddies boat tonight and see what that tells me… hopefully that will tell me either my truck or my trailer is where the problem is.

I have a little connecter that fits on the 4 pin connector, with little LEDs on it, that tell me if the lights are all working correctly, Works great, you can find them at gander mountain.

I still think it’s a fuse problem, did you check to make sure there isn’t 2 fuse boxes on your truck? I know most trucks have one under the dash and under the hood too. Last time I had problems it was the one under the hood.

Is it possible you have a short somewhere in the line? did you just replace the lights or the lights and wireing going to the lights?

Last year I totally rewired my trailer, I used outdoor extension cord as my wiring running inside my trailer tubes, so I know that I will never have a short on my wiring now, basically it would take too long to rub though the outdoor extension cord coating and wiring.

I CAN’T BELIVE IT OFFICER, THEY WORKED FINE BEFORE I LEFT, I CHECKED THEM

I may have to look again at my fuses… I did look at both panels, under the hood and side of dash. Now that you say that I need to investigate the fuse or flasher that runs my hazards… for some reason they would not work lastnight. I didn’t try to turn the hazards on with the trailer lights unhooked to see if that would have made a difference. I guess I over looked that… maybe that has something to do with the problem.

I really doubt that the wires have a short on my trailer… I have the wire ran thru a clear plastic/rubber hose that is exposed, I did this so rocks and vibration didn’t damage the wires. I looked for any places that might have been pinched or damaged and didn’t see anything.

thanks for the ideas guys.

Quote:

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I CAN’T BELIVE IT OFFICER, THEY WORKED FINE BEFORE I LEFT, I CHECKED THEM

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I am not worried about that, I am more worried about somebody making a hood ornimant out of my outboard!

Most likely the problem is in the trailer, but I would start with either a test light or voltmeter and make sure the vehicle’s plug is doing what it should.

Next, make sure you have a good ground on EVERY light fixture. You may even have to check the internal electrical connections in each light. Dunking them in water causes a lot of corrosion. One way to help check for ground problems is to run a temporary (or permanent) ground wire from the fixture up to the plug.

After checking everything out if you still can’t find the problem or it is not dependable, I would recommend installing a new light system.

hey give me your phone number on messanger I can give you a call and help you out. also make sure you have a test light handy.

Once you finally get your problem fixed, use some dielectric grease on all connections. This helps greatly slowing corrosion.

Lastnight I hooked my truck up to my buddies boat and had the same results. Everything on the passanger side worked but the drivers side would only lite when I turned on my head lights… no brake, no turn signal on the drivers side.

I am thinking its something on my truck that is messed up.

I rechecked all my fuses, cleaned up the ground wire in the rear of my truck that hooks to the frame.

I don’t know if these things would be related but for some reason when I turn on my hazard lights the front passanger side will not work, but it works when the turn signal is on.

any ideas there, or thoughts on a connection between the 2 problems?

I hate wiring!!

do a google search, enter “troubleshooting wiring problems boat trailer”, lots of FAQ’s and answers.

Call up a local rental or trailer place. These guys have seen it all before and can have it fixed for pretty cheap. I used to work for an electrician, and we brought all our trucks there for wiring! They are so knowledgable about that stuff they can have it done very quickly.

Good Luck.

The problem has to be with your truck. Sounds like left rear running and taillight issue. Call your local dealer, and see if you can get schematics of the wiring for your truck. I print quite a few here, for DIY guys. I would say the hazard in Front is another whole issue. Good luck.

big g

Got it!!

put a new tee plug wire harness on it and the trailer lights are working finally!

I think the hazard thing is another issue… a buddy of mine thinks it is a bad wire or switch in my steering column.

but as long as I got trailer lights I am happy.

thanks for all the ideas guys!!

Yeah, good for you I think you jinxed my truck
The car still works fine, but something is funny with my lights too, and I checked all my fuses, I think I’m just going to replace the wiring going to the back, well see how proud ford is of that stuff