billschroeder5842

My back up lights don't work on my 91 ZR1. While not critical, it still bugs me. This will be my Christmas weekend project.

I checked my bulbs on near the licence plate and they are good, but no power. I checked the electronic service manual and everything connected to the back up light system is working, except the rear lights.

That leads me to believe that the back up light switch is defective? I see the switch is located near the top of the transmission, driver side. Is this something that is pretty easy to get at? I'll be jacking the car up and laying on my back as I don't have a lift.

Will I be able to swap it out with limited space, or will I have to suck it up and go to a shop with a lift?

WVZR-1

M22 or some may actually use 7/8 but can be done without lift. An M22 or 7/8 crows-foot for O2 sensor might work well. I've never tried one. Not a pleasant experience but doable I believe. You might check the connector first and very likely only the "detent ball" ball on the switch is stuck. In most cases a good soak, exercise the "detent ball" after removal and the switch will return to service. You can check it for operation in your hand.

Have you shopped for a replacement? Last I knew it was a very tough find.

Kris_K

I tackled this job a few years ago. Access to the switch is limited making replacement a bear. I agree that you should try cleaning the detention ball after removing the switch to see if it's just gummed up. Reinstall and see if works after cleaning.

DRM500RUBYZR-1

Ecklers used to carry a replacement switch.
it was designed a bit differently to make installation and future removal a bit easier as it was smaller, and easier to get around it.

Marty

FASTAZU

Done with the conflicts here..............................

billschroeder5842

Any tips for taking it out? I poked around enough this weekend to know that it is a PITA.

I'm sure is was listed in the FSM, but I could not find it.

Attack from the top or attack from underneath? I really can't even get a good eye ball on it.

WVZR-1

I'm quite confident of the M22 or 7/8 can be used so I'd think this isn't going to do the switch. For sure it will do the drain/fill but the M21 dimension on the 12 point I'd doubt is going to do the switch. I believe I've actually measured a switch and maybe later today I'll be able to do it again.

OP - You might be able to remove the connector with some very long reach needle-nose but then you could actually only confirm the wiring so.

The switch that "Marty" mentions is likely still out there and maybe a buy from Amazon. The Amazon offering is actually by Corvette Central I believe. The HEX on the CC/Amazon could very well be different so maybe you'll need multiple tools.

https://www.amazon.com/1989-1996-Cor.../dp/B00I5UFEWQ

This post and thread has good information I believe.

https://www.corvetteforum.com/forums...post1584680990

FASTAZU

Well I'm sure I must be mistaken ................ I'll just keep doing things my way no need to share....I only stated working on Corvette's in 1977.....

WVZR-1

If it works it works!!! Can't argue with what's said to work ...

I just measured a switch here on all three sets of "flats" M22.08, M22.04, M22.07 multiple times. .867 +/- or so sae. An M21 - 12 point maybe.

KaKruisin

I just replaced the switch on my 93 ZR1 a couple of weeks ago. They are known to fail. If you search history here on the forum you can find some tips. I used the replacement switch from Corvette Central - same switch with a pigtail that makes it a little easier. The tool is 7/8" box wrench with an offset (I got a set of these at Harbor Freight for $13). It helps to move the slave cylinder out of the way (2 bolts). Then disconnect the wire, then with the right tool, the switch can be taken out. Put the new one in, tighten, connect the pigtail, reattach the slave and your done. After reading about the process and getting the right tool, it took about 30 minutes. That said, I have a lift in the garage - I suspect that it will be much more difficult on your back.

billschroeder5842

Thanks- this info helps me a lot.