brake lights not working, checked fuses and bulbs.

[02tahoe218s]

Hi guys,
Im new to the the site so if Im in the wrong place let me know but i have an issue that i cant figure out. I drive a 2002 tahoe and my brake lights do not work. the Center high mount brake light still works properly, all fuses i can find for brake lights are good. Ive changed the brake switch and the box under the truck above the exhaust. and still nothing, turn signals,hazards and tail lights still work fine. I have test lighted the wires at the brake switch on the pedal and they all have power, accept the ground. lol. is there a fuse box under the back seat? i have been told by a local chevy dealer there should be one under the back seat but i can not access this at the moment because of my stereo equipment. i have also test lighted the plug at the back where the bulb is inserted and i have no power there. i have also tried testing the wiring under the truck at the box that i replaced but cant seem to get any power there at all for anything. i also replaced the turn signal switch when i bought the truck because i did not have cruise control. that fixed the cruise at the time but now i lost the cruise again also. anything i can try will help. thanks guys

 

[Coatwolf]

I've yet to have this problem on any car except and old vw... Is there anything at the master cylinder that's become disconnected? This seems strange....

 

[SLCHOE]

Your brake switch is good if the high-mounted center brake light is working. We can eliminate everything up to there.

Here are the schematics:





Two separate circuits feed the stop lamps and the center stop lamp.

Recheck your fuse for "VEH STOP" (10A) that feeds that circuit.

Having checked that and assuming it's good, check the connectors at the tail-light junction block. This in a place where the connectors can get very dirty and/or corroded. Pull the connectors off and inspect them. Make sure they are clean and if not, clean them with some electronic terminal cleaner or carb spray. Reconnect and then recheck your fuses. Then check brake lights again.

Here is a video of the junction block.

https://www.youtube.com/watch?v=EICo1WwxvII

 

[02tahoe218s]

I had replaced the block in the back earlier on when I originally found out about the issue. I cleaned everything when I re connected the wiring. But I went back under truck to examine each of the plugs much closer. I noticed On the blue plug there was a broken wire, and also that the prong on the connector was corroded. I havnt had the chance to fix the breake yet but I test lighted the wire and nothing happens. Whether somebody is pressing the pedal or not. Nothing happens on any of the wires on any of the harnesses. Shouldn't something light up, somewhere? I noticed I have also lost my center high mount brake light also now. I will know more tomorrow.

 

[02tahoe218s]

I forgot to mention the color of the broken wire I found. Lol, it was a blue wire on the blue plug