Trailer Light Issue

[mawint]

Hey Peeps,

 

Having an issue with the trailer lights when attached to my truck. I'm on mobile but it used to be listed on my profile but I have a 2004 Avalanche z71.

 

Anyways, this happens with multiple trailers and the only constant is my truck. The current trailer I'm using has had new lights installed and was tested on my truck and another. The other truck worked great.

 

The issue I'm having is that with the headlights on the clearance and tail lights turn on but if you hit the brakes or the turn signals, the lights go out. The lights work fine as long as headlights or running lamps aren't turned on. This leads me to a ground issue but I cleaned the 7 pin on the truck and the ground near the drivers side taillight without positive results. I also changed the 4 pin to 7 pin adapter as the old one was starting to corrode some.

 

Does anyone know of any other grounds related to the trailer wiring? I checked all of the fuses as well.

 

One thing I haven't done but probably should have is get one of those testers with a lamp but it still won't show me where the grounds are.

 

I attempted to search but didn't get any good results.

[rjgti]

check above your spare tire

[slj2008]

Check your hitch ball , is it new or a rusted one ???? clean it up and recheck your lights . with a test light check both side of plug , you might have a lose wire on the back side.

[mawint]

What am I checking above the spare? I followed the wires but didn't see anything there.

 

I have two hitches, one is slightly rusted, one brand new. Did it with both of them. The hitch itself is a little rusty though. I could clean it out and retry.

[Plugger49]

Hey mawint, are you still around? I was wondering how you made out. I had very similar issue.