Upper Brake Light (91)
 

Just joined the ZR-1 club with an 11k mile Red/Red '91 last week! First prob is the upper brake light not getting power (failed inspection) any hints on how to locate/check switch on brake pedal or other possible "easy" fixes to check out?

Do you have a service manual?You may want to start by checking the grounds..

I have the basic 91 service manual, it refers to an electrical suppliment on testing this circuit, which I do not yet have. Also looking for a ZR-1 supplimental Service Manual now that there's an LT5 is the garage.I'll check the basics, just thought someone might know a short cut or common problem I could check first. Just have not had time to dig into it as I'm doing a little final work on the 91 coupe for sale this Friday.Thanks for the reply!

Here is what the book says to check..1.Backprobe the brake switch connector with a test light between term “b” and ground. Is the test light on? YES2.Backprobe same connector with test light between term ‘a ‘ and ground and between term “c” and ground.3.The test light should illuminate at both terminals when the brake pedal is depressed. YESFor high level stoplamp check for an open in CKT20 or ground CKT150If NO for #1 check for open or short to ground in CKT140. Check for open stop/haz fuseIf NO for #2 check for proper adj. of brake switch.Hope this helps..Steve

Just went thru this. Most likely a bad brake switch.

THanks guys I'll work on it this weekend and let you know how it goes. Looks like the backup switch is bad too, no backup lights either. Heard that's common on these too.

Yep it was the brake switch. Another ZR-1 owner worked with me to change it out. Both of us over 200#'s so taking the seat out was required to get to it.Works like a charm now as does the new back up light switch and hood latch.

tell me about the reverse fix. Mine is not showing. I pulled the lights in the back and they look fine. I did not spend any more time on it yet but it be nice to listen to anothers war story.

We put it on a lift and replaced the back up switch (about $40 from GMparts direct.com). Luckily my buddy has a 91 ZR-1 too and had already replaced his so he knew the drill.The switch is up high on the left side of the tranny so its almost imposible to get a wrench on it. We used a piece of pipe to knock the end off the old switch (after testing the new switch to be sure it activated the b/u lights) this let us get a socket on it with a couple of swivels and about an 18inch extention.Pulled the old one (had to remove the clutch slave cylinder to get to it and found the dust boots in that to be loose, fixed them too). Then the fun started, had to use a pair of vice grips on a deep socket to get the switch back in.All this would have taken me all day but Jeff had done it before and using his lift we had it done in about 15 minutes! Its great to have friends with lifts and mechanical ability!