Trailor Left brake light problem

[truckmann]

I have a problem with my left brake light trailor wiring not working. It works when it wants to

 

It seems to work until I use the left blinker and then no brake light. I can get it work again if I tap on the interior drivers side fuse panel. I noticed there is a large flasher modual in that back of that panel, behind where stop and turn signal fuses are for the trailor lights. I am wondering if I may need to replace that flasher module or if there is something else wrong.

[95Sierra2500]

If it only happens when you're towing a trailer, I'd look for bad wiring around your plug in on the truck and anywhere on the trailer. I doubt it's a fuse/relay problem.

[whmayhew]

I would check for a bad ground on that particular light. Bought a new camper 2 1/2 years ago. It did the same thing. The dealer told me to tighten the ground wire. It took care of the problem.

[the blur]

T-r-a-i-l-E-r

 

you need a new turn signal switch.

[truckmann]

I tracked it down to the flasher/blinker module. All power for the for the trailer wiring goes through that module, and when the brake light doesn't work there is no power to that particular fuse in the panel. There is nothing wrong with the blinkers or the turn signal switch, if there was then I don't think taping on the fuse block would without fail restore power to the brake light. Of course that module happens to be expensive and I don't thing the aftermarket parts places sell them so I order one from GM parts direct.