I think I have tried everything, please help !

[weeboat]

Hi All,


First time ever with so many issues with trailer lights. However, first time using truck with tow lights installed, kind of.
Want to make sure I give as much info as possible, although after 2 days I am a little fried.

Chevy Trailblazer with 7 pin to 4 pin adapter.
Small 14 ft trailer, standard lights.

Issue: First, I used this truck last summer, maybe 4 times, with the same trailer. After 3rd time, lights were flickering. Shaking the ground wire to trailer helped.

Now: Bought new lights; old ones were shot. So wires have no slices except on side lights.
Old ground screw was not working, so used a self tapping screw with ring connector heat sealed in different location.

When plugged in, it was crazy. Both sides blinked, side markers didn't work. And brakes, shut all down.
Ok, bad ground.

Redid ground, adding washer and dielectric grease.
Same issue.

Went to truck side. Checked fuses, a fuse was out, a turn signal. Replaced fuse and checked adapter. All worked.
Plugged in lights and used light tester, all worked.
Yet, lights did the same thing.

Got OHM tester, checked for resistance. At harness, ground was okay, Rear lights were not.
Added another ground to both tail lights. Again with self tapping screw etc and wire rings both sides, dielectric grease.

Okay, so brake does not shut down lights, markers work, yet blinkers go on both sides.
I noticed, since I have DTR lights, I must turn them off and turn lights on regular and it seems to make a slight difference.
But blinkers still working both sides. One side brighter than other side.
Seems like side markers are blinking slightly as well.

I realized I had a rear reverse bulb on truck lights out and went to change that and saw the running light bulb was black, but working, so changed it.

Still have the same issue.

Am I missing something???? Could the harness I just bought be bad? Even though it checks out fine with light tester???

Is there another fuse I am missing? The one I replaced was in engine compartment, There is another box under seat. One fuse in there I dont think I checked. #42 Trailer Park. Which I think is the running lights.

The trailer has been used before for my other small boat, never an issue. The trailer was painted black by previous owner. So I used the dremel to make steal show. It is also a tilt trailer.

Any suggestions at all would be welcome. I am about to find a place to do it. Most are not close by though.
UGH !!!!!!!!!!!!!!!!!!!!!!


Thank you for listening,

 

[ajax5240]

Re: I think I have tried everything, please help !

Clean the paint off the ground areas so that the connector can touch bare metal. Then paint over the connector area so it doesn't rust. Do the same for the ground at the tongue right off the plug and all the grounds at the lights.

If you have a meter, check that there is infinite resistance on all the power wires to ground, to verify that you don't have a short.

When pulling a new harness into a trailer you can peel insulation off a wire and cause a short to ground.

Good luck, and keep it simple!

 

[etracer68]

Re: I think I have tried everything, please help !

You also may have to clean the area for the tilt pin. If you took out a fuse, you have or had at that time, a dead short, that may not be touching all the time. I had a buddy (may he RIP now) that sore up and down he had the colors right on his lights, and he was color blind, but said he could tell by the shade of color, but had them wired wrong when I took a look.

 

[Grandad]

Re: I think I have tried everything, please help !

I had problems similar to what you describe back when I was a teenager with his first boat. Now a retired electrician, there's one thing I've learned to do with every trailer I've since owned. Don't ever depend upon the trailer frame ground. It'll drive you bonkers. Run a continuous ground wire to every light fixture. At the fixture, you'll likely find there's no wire available to directly connect to the ground wire you just ran, but you should still run it. Terminate the wire directly onto a screw on the metal frame of the fixture. As always, make sure the termination is clean and tight, then slather some dielectric grease onto the area.

Once you're assured of good grounding, only then can you efficiently troubleshoot. One troublesome part of using an ohmmeter to check trailer lights is that since all the lights are connected to a common point on the frame, your ohmmeter can see a current path through more than one light bulb filament to ground. Depending upon upon where the break is in the ground path, you'll get deceptive values showing on the ohmmeter. - Grandad

 

[weeboat]

Re: I think I have tried everything, please help !

Thanks guys.


I did use an resister test at each ground and on trailer. Got a zero. (have ground from harness and then a ground for each tail light)
I also used the dremel to get paint off.

Cleaning the tilt pin, never thought of that, will do. But since I have never had a problem before with tilt, I did not run a ground from harness to lights, just from each tail light.

And yes, I was also thinking wires may have gotten peeled / scraped, when I used the self tapping screw for ground by tongue, the other wires run through there.

Since I have never had an issue and I am now using a truck with tow package, I was starting to think it was something on that side. Since the day time running lights seem to affect things.

Will recheck fuses and resistance and tilt pin.

What a headache,

 

[weeboat]

Re: I think I have tried everything, please help !

I just checked again for resistance, should be a zero. I get negative zero at all grounds.
Is that possible???

Once you're assured of good grounding, only then can you efficiently troubleshoot. One troublesome part of using an ohmmeter to check trailer lights is that since all the lights are connected to a common point on the frame, your ohmmeter can see a current path through more than one light bulb filament to ground. Depending upon upon where the break is in the ground path, you'll get deceptive values showing on the ohmmeter. - Grandad

 

[Grandad]

Re: I think I have tried everything, please help !

You can quickly confirm if grounding is an issue by stringing a length of wire on the ground (even an extension cord would do) to connect between a known good ground and a light that's not working right. Saves time and reduces headaches. - Grandad

 

[weeboat]

Re: I think I have tried everything, please help !

WOOHOO.....

Thank you guys...she is working.
I did 3 additional things.
Cleaned adapter harness, although it looked clean and did check out with tester.
My truck had running light bulb out, changed it.
Did not use daytime running lights, turned them off and used as regular lights.

Now it all works. What a freakin nightmare.
So now just hook up lights with connectors. ahhhh
So glad this forum is here and you guys are so helpful. Even if I already tried something you suggested, its good to see others opinions. Makes ya think and makes you feel comforted you are not alone.

THANK YOU !!!!!!

 

[ajax5240]

Re: I think I have tried everything, please help !

I just checked again for resistance, should be a zero. I get negative zero at all grounds.
Is that possible???

Sounds to me like you have your meter on the wrong setting. There is not really such thing as negative resistance. Sounds like you have it on voltage not resistance.

To do these types of tests you need a long jumper wire. I made a set out of some wire and alligator clamps at both ends. That way you can clip the jumper to your frame ground by the hitch and be able to reach the ground wire on a tail lamp to see how much resistance is in that ground circuit. Set it on the 200 ohms (or your similar setting) the lower the reading the better, a perfect circuit would have zero ohms resistance. But that would be gold or something. The wire will have a few ohms per foot, and your connections all will have a little resistance. If a circuit is "open" or not connected, it will have infinite resistance your meter will say "OL" which is out of limits. Or whatever if shows when your meter leads are not touching. To test it, touch em together and it should read close to zero.

Hope that helps you understand the testing a bit better.

You can use that same test for any broken wire just make sure not to have power connected to the circuit while testing

 

[LippCJ7]

Re: I think I have tried everything, please help !

Well if nothing else now you know why GOOD electricians are normally bald or grey or suicidal or schizophrenic or....


Are you having fun yet?

 

[Grandad]

Re: I think I have tried everything, please help !

Well if nothing else now you know why GOOD electricians are normally bald or grey or suicidal or schizophrenic or....

... retired.