Skyking

Ok, i've attempted to try to fix this problem myself but need help.

First, the turn signal, hazards and bake lights went out, so i tried changing fuses and they kept blowing. So i looked online and read through a lots of post on different websites, and decided it was the multi-control on the left side of the steering wheel. I changed that out, put in new fuses and everything worked well for about a day. Then the turn signal started blowing fuses so I changed the flash relay under the dash. That seemed to solve that, has blown any fuses since I put that in (3 days ago). Then the brake tail lights went out, so I changed the brake light switch(under the steering wheel) and the relay (under the hood) but still no change. (i've kept looking online to try the different tips everyone has used to get their light working). so, then I changed out the tail lights sockets (circuit boards), and disconnected the trailer plug. I did use a tester on the plus wires and received amperage on both left, right and park wires, but none on the brake. Then I located the main connector, from the main wires from the front, just behind the spare tire and teased the power there. And it was the same, only left, right, and park but no brake. I traced the wires back pass the tank, fuel filter, cab, and up to the engine compartment, and they looked fine. The third brake works, both turn signals, and hazards, as well as parking lights.

And now, I am completely clueless as what to do next. I did check the voltage and amperage at the fuse box (between the door and dash) and its 12 volts (roughly) and 185mA..

any ideas what to do next? or if anyone has the brake light wiring available, I would greatly appreciate it.

basic run down of all parts replaced
multi-function on steering column
brake light switch
brake relay
flasher relay
all bulbs (third brake, both right and left tail lights)
tail light circuit boards
fuses

1997 Chevy Z-71 4x4 extended cab automatic with 5.7L engine, no modifications other than cosmetics

skeeter5

GM UPFITTER - Body Builder Manuals

This may have what you need.

The manual for my 2011 is 785 pages.

This is a great source for information.

Should you want to down load the whole manual, read the information on the left side. The link refers to the red letters in the subject info.(menu)

I hope this helps getting your truck going.

Mudd Mutt

Cut off your trailer harness. Sometimes water gets in there and shorts it out. Worked once for me and it doesn't cost anything so you might as well try it

Skyking

i went and cut off my trailer plug, and at first, it didn't do anything. So i stopped by a nearby auto shop, i figured they had better electrical testing equipment then my multimeter and probe. And they tested the wires and narrowed it down to the maxi 30amp fuse under the hood, next to stop relay.

Apparently, the wires in the trailer plug wiggled loose, and caused a short. It caused the 30amp maxi fuse to burn out (although it did not have the tale-tale blow link or black spot), once the tech replaced the fuse, the lights began to work. So now everything work well.

thanks to Mudd Mutt and skeeter5 for their help.