Trailer Lights Problem

[LuckyTri]

OK, last weekend I had another issue with my trailer lights after taking my boat out of the water. This was the weirdest yet. I am sure it has to do with wet parts as it only happens when pulling the boat of the water - when it's dry it is always fine. Just what wet parts is escaping me.

Last time I started with no running lights, but I had brake and signal lights. Then the left brake and signal light also stopped working. Then it started working but still no running lights. The next check gave me running lights and break/signal lights on the left only (the right brake/signal lights which had been working all along had now quit and this was an hour later). That right brake/signal light was still not working at bed time, but by the morning it (and all the others) were working again.

When I get these problems I open up the lights and drop the innards out and try to dry them, but it doesn't seem to do much. It certainly didn't last week. The shop suggested replacing the wiring, but I am sceptical about that.

Any one have these kinds of problems? Any pointers to help diagnose this problem would be much appreciated.

(BTW, the trailer was brand new Sept 2005, and gets dipped in the water once or twice a month - I know, I know, I don't get out enough! The bulbs are all working, and the sockets still have gel in them to resist the water. )

LT

[Wallyboss]

I usually disconnect my trailer lights when I put the trailer in the water.
you could try installing waterproof light housings. You can pick them up for a good price at Princess Auto.

[1lastcast]

I would put my money of a bad ground wire. it is the white coloured wire that will be attached to the trailer frame. take a look at that first before you go replacing the wiring.

Just clean up the connection you may have to even attach the wire with a new self taping metal screw to the frame of the trailer.

It wouldnet hurt to try the boats wiring on a buddies truck. It could be that your truck is to blame?

Get yourself some dielectric grees from canadian tire and cover the wire harness and any exposed conections with it. it will help to keep mositure out.

let us know when you solve the problem. trailer wiring is always a pain in the butt. I had a snowmobile trailer that always seemed to give me hard time. usally when it was -20

good luck

[LuckyTri]

Thanks for the suggestions!

A couple of people have suggested the ground wire might be the problem, but if it was wouldn't all the lights not work? How would the running lights work but not the brake lights, or the brake lights work but not the running lights? (My lights have one ground/white wire off each light housing that serves both the running lights and brake/signal lights.)

And yes I do unplug the lights before backing the trailer in.

There is grease in the bulb sockets, but I'll try adding some over the other contact points on the harness.

Waterproof housings sound like a great idea - why wouldn't they be standard?

LT

[mikemicropterus]

Try cleaning the individual grounds of the lights. Each light grounds to the trailer and then the trailer grounds to the vehicle so if the grounds on the lights are bad then that light will try to ground through another source being the cicuit of another light. ie when I turn my signal on my running lights come on because the signal is using the running light circuit for it's ground.

CLEAN ALL YOUR GROUNDS

[mdej]

These are annoying problems to figure out.

Seems you have done lots of trouble shooting already.

I'm starting to think that maybe either the socket connections to your tow vehicle is not connecting correctly. Clean the dirt out of both ends of the plug, spray with some brake cleaner and compressed air to get all the crap out.
Debris in the plug can cause these connection problems.

Also check the wiring on the tow vehicle to make sure its not banged up and shorting out on the chassis.

[mikemicropterus]

It will take me 10 minutes to figure out your problem!!!!!
You just need to know how to and where to look.

Michael

[Graembo]

I had issues for years. Princess Auto & $90 on the LED waterproof kit is the best thing I've ever done for my sanity. It took an 1.5 hrs to install the lights/wiring and you can leave them plugegd in backing into the water with no issues whatsoever. No more bulbs blowing or any headaches!

*BTW They look just awseome @ night to boot!

G

[LuckyTri]

Thanks to everyone for your sugesstions

I think mdej got it, only I think it is the plug on the trailer that's corroded, not the tow vehicle. I keep the tow vehicle plug inside the rear hatch safely tucked away when not in use and it's pretty clean and looks like new, but the trailer plug is exposed to the elements and the contacts are a flat, dull, grey colour. I used an ohm meter to test the trailer circuits and when I applied the point of the probes firmly to the contacts I got a good test, but when I used the smooth side of the probes on the contacts I didn't get a reading. So I scuffed up the contacts a little and redid the test and when I touched the side of the probe to the scuffed area I got a reading.

So I will thoroughly clean the plugs (tow vehicle too for good measure) and see how that goes.

Any suggestions for the best way to clean that corrosion off the contacts (aluminum)?

LT

[OTRA]

I made up a simple test kit. I used a spare plug (vehicle side), that I picked up from the local auto parts store, and a 12v power source (I've got a the portable 12v jumpstart, but any 12v battery will work). Plug your trailr plug into the truck plug and Hook up its ground. Then one at a time you can test each light individually, without having to be inside the vehicle hitting the brakes,turn signals, etc.

[LuckyTri]

OK, I followed OTRA's suggestion and hooked up a spare battery to the trailer. All lights worked fine. So I tested the voltage on the plug from the car - all looked good. Then suddenly things changed. I wasn't getting consistent readings.

To make a long story short, I replaced the electronic gadget that isolates the car electrical system from the trailer. I guess just patching the trailer into some vehicles can interfere with vehicle circuits, including ABS, so some vehicles need this unit to prevent these issues. My unit appears to have gone faulty but rather than just fail totally, it was producing intermittent voltage and current drops. Once the new one was hooked in, all worked well.

The original installers hadn't put in a fuse in front of the unit (as specified in the instructions) so that may have had something to do with it. I put a fuse in this time.

LT