Kind gentlemen...need help on shocking issue>>

[ZR1Vette]

Well not so shocking which is somewhat the point. The center brake light has stopped functioning and this is the diagnostic so far:
-disconnected the plug under the halo trim (the was a PIA to do...have to remove the drivers side interior halo trim piece to get to plug) and sent 12v to light unit and it lit up...so the center light itself is functioning
-place a DC volt meter on the wire leading to light fixture plug...stepped on brakes and no current

Conclusion... (1) open line in wiring from ???? to light (2) wire is connected somewhere to work with rear brake lights and connector is loose or (3) ???

Anyone know where the wiring for the center brake light goes to in the dash?
Assume there is not separate fuse for center brake light (could not see such in the fuse panel on the passenger side dash end)??? Any thoughts on what or where else to trouble shoot??

Of course would totally appreciate any assistance :cheers:

[gbrtng]

I think there is a separate brake pedal switch for those lights. I don't have a 90 FSM so maybe someone else can jump in ...

[Jagdpanzer]

Does it work with the hazard flasher?

[LT5-Lee]

There is definitely a separate 3rd brake light switch, I had to replace mine. I bought one at the local auto parts store. I thought at first it was threaded in, but thank goodness it is just a matter of disconnecting the pig tail and either using a small hook tool to pry open one of the stamped shaped retaining fingers or just giving it a good yank and pulling it out. To install, hold the brake pedal up against it's rest and pushing the new unit in until it rests against the brake pedal.

[Jeffvette]

There is definitely a separate 3rd brake light switch, I had to replace mine. I bought one at the local auto parts store. I thought at first it was threaded in, but thank goodness it is just a matter of disconnecting the pig tail and either using a small hook tool to pry open one of the stamped shaped retaining fingers or just giving it a good yank and pulling it out. To install, hold the brake pedal up against it's rest and pushing the new unit in until it rests against the brake pedal.


3? Should be 2. One for the cruise disengagement and the second for the brake lamp function. Then there is a third one, but it is mounted on the clutch pedal fro cruise disengagement.

There will be three wires in the switch.

Orange power
White which leads to the lower 4 brake lamps
Light Blue which leads to the CHMSL

The wire will follow the body harness. Check for breaks in the circuit at the pedal and the bulb. And go from there.

[ZR1Vette]

Thanks for the info...will check out the switch etc today. Phil...everything works (including emergency flasher) EXCEPT the center brake light.

[ZR1Vette]

Alas, no fix. Will be taking ZR to a specialist and let him work it out. First glitch I could not resolve... oh well :neutral:

[Aurora40]

How did you verify it wasn't the problem? Did you get a new switch? If so, did you replace the correct one?

The switch causing the 3rd light not to light is extremely common from what I can tell (had to do it on my car when I got it). There aren't really any other moving parts, except maybe the wiring through the hatch.

[Sgreg]

Well not so shocking which is somewhat the point. The center brake light has stopped functioning and this is the diagnostic so far:
-disconnected the plug under the halo trim (the was a PIA to do...have to remove the drivers side interior halo trim piece to get to plug) and sent 12v to light unit and it lit up...so the center light itself is functioning
-place a DC volt meter on the wire leading to light fixture plug...stepped on brakes and no current

Conclusion... (1) open line in wiring from ???? to light (2) wire is connected somewhere to work with rear brake lights and connector is loose or (3) ???

Anyone know where the wiring for the center brake light goes to in the dash?
Assume there is not separate fuse for center brake light (could not see such in the fuse panel on the passenger side dash end)??? Any thoughts on what or where else to trouble shoot??

Of course would totally appreciate any assistance :cheers:

Brake light switch needs to be replaced. A little tough to get to under the hush cover, drivers side.. Part is about $15. Good luck.

[Z51JEFF]

Mind was dead and turned out to be the switch,pretty common from what I hear.

[ZR1Vette]

Good info all...will get a new switch and replace. Would be great if that is the problem as opposed to a damaged wire somewhere between switch and CHMSL.
Really do appreciate the assistance. After switch install will let you know results... will be either :cheers: or :mad:

[ZR1Vette]

Well, I have the switch of issue on order (will be to me on Monday)...but with that said my dealer indicated it is a 'discontinued' item and they found a dealer on the West coast that had one in stock which they purchased. Wow..parts are becoming more and more scarce (considering the brake light switch is NOT specific to the ZR-1 but C4 in general)

[Jeffvette]

Well, I have the switch of issue on order (will be to me on Monday)...but with that said my dealer indicated it is a 'discontinued' item and they found a dealer on the West coast that had one in stock which they purchased. Wow..parts are becoming more and more scarce (considering the brake light switch is NOT specific to the ZR-1 but C4 in general)

You can also pick them up at napa or autozone.

[jrd1990zr1]

Well, I have the switch of issue on order (will be to me on Monday)...but with that said my dealer indicated it is a 'discontinued' item and they found a dealer on the West coast that had one in stock which they purchased. Wow..parts are becoming more and more scarce (considering the brake light switch is NOT specific to the ZR-1 but C4 in general)

Very common problem on C-4s. Sometimes the switch slides in the retainer and doesn't make contact with the pedal. If it has just slid, try pushing it into the retainer so the pedal make contact. I have also removed the switch and cleaned the contacts inside and reinstalled it on my 86 that fixed the problem.

Ecklers and Corvette Central have the switch available too, $10-15.00

:cheers:

[ZR1Vette]

I obtained a NOS ACDelco brake light switch from a 'special supplier'... installed this morning along with changing out all the fuses in the main fuse box (passenger side dash end)... appears the switch was the culprit and all now is working... thanks all for you knowledgeable guidance on this issue :handshak:

[Jagdpanzer]

Glad you got it solved Michael

[LT5-Lee]

I stand corrected, I just had a situation where only the brake lights above the window was not working.

[black90]

Had same problem. Checked fuses - no problem. Changed all 4 bulbs in high mount light - still didn't work.

Decided it had to be the switch for the brake lights - seems it is a two part switch. Took cover off (the under the steering wheel) and replaced the switch. That did the trick. Have to be a bit of a contortionist to do the job, and it took some time to go through all the motions. It worked and I could get the inspection sticker.