Trailering Problem

[ChrisCapePoint]

Hey guys...first post here.

I am on my 3rd Tahoe/Yukon and have loved each one. Have never had an issue trailering before, but have run in to a problem that has left me scratching my head.

When I hooked up my trailer the other day...

I tested the emergency flashers just like I always do, with the truck TURNED OFF. Lights worked fine. Cut the truck on and had the wife push on the brakes, turn signals, etc...NONE WORKED WITH THE TRUCK ON. Turned the truck BACK OFF, and after a minute or two turned the emergency flashers on, and again they worked fine, with the truck TURNED OFF. So again, I cut the truck on, and NOTHING!!!

Checked the fuses under the hood. Both were good, but replaced both anyway. Still having same issue...

HELP!!!!!!!!

Thanks in advance!
Chris

 

[bkboatnsleds]

few questions...

When thew truck was ON was it dark out? were the running lights on?

My guess is that the problem lies in the trailer, and when the truck is on - the running lights were shorting something out. 9 out of 10 times the problem is in the trailer. I tow more than I don't and it always works out this way. Especially in the salt region im in.

You need to be SURE this is the case first. So un-plug it from your truck, and plug a test light in, or use a handy tester like this:

Once you determine the problem is NOT the truck - move on to the trailer. I use a set of test leads and a battery. Connect the trailer to the ground, and then manually test each pin on the connector for the lights, chances are you'll find one of them does not work and or shorting out another circuit on the lights.

Also if your truck IS in fact the problem - don't forget there are fuses under the hood for some of the trailer harness features.

If you have access to this - its a huge help too (If you know how to use it)




Let me know if I can help.

 

[MrBalll]

Did the brakes/blinkers work with the truck off?

 

[ChrisCapePoint]

Thanks for the info BK. I will pick up a test light ASAP. What you said about the running lights makes sense.

I tried both during the day, and at night. And have tried turing the lights on manually, as well as using the auto lights (day and night).

When I have the truck off (totally off with key out)everything works. For instance, say I have the emergency flashers on...as soon as I insert the key and turn the truck to either the ON position, or turn it over to start the truck, the trailer lights go dead, totally.


MRBALL...The brake lights work with the truck OFF. The blinkers don't ever come on with the truck off, so I don't think there is a way to test....

 

[bkboatnsleds]

is the connection a 4 pin flat? using a converter? Or is it a 7 pin? Electric brakes? What kind of setup do you have?

A short somewhere can make it do goofy things!

You need to do your same exact tests w/ the test light.... if the lights all work with the truck off, then turn truck on and check the test light again. need to determine if it acts the same w/o the trailer or not.. then we at least know where the problem is.

 

[Rivieraracing]

Have you towed this trailer before successfully without light problems? Other trailers with this truck?

 

[ChrisCapePoint]

Have you towed this trailer before successfully without light problems? Other trailers with this truck?

Have towed this trailer with both of my other Tahoes with no problems...

So...

I used a tester...It had the Trailer, Left Turn and Right Turn indicator lights...both turn signal lights worked. Trailer light did not.

---------- Post added at 08:47 PM ---------- Previous post was at 08:23 PM ----------

is the connection a 4 pin flat? using a converter? Or is it a 7 pin? Electric brakes? What kind of setup do you have?

The setup is a 4 pin flat, to the trailer, using the converter. Same one I have had on all 3 tahoes, using the same converter. Everything worked fine with both other trucks using the same converter.