1985 Blazer, 5 speed manual transmission. Both backup lights not working. Checked bulbs and are good.
Need to find the location of the backup switch and want to start there and see if I have a bad switch or wiring..

 

Mostlikely is the switch. It should be located on the transmission. I don't have access to my references at the moment and won't until really late tonight. Hopefully someone else can answer you sooner...

*Moved to 1st Gen Tech*

 

Yep the switch is in the side of the transmission..passenger side IIRC, but it has a 2-wire connector. Easy andquick diagnosis, key on, unplug the connector from the switch, install a fused jumper wire across the 2 terminals of the connector, and the lights should turn on. If so the switch is bad.

 

Jumppered the wires,, and lights came on..Looks like the switch is bad...
Is there and special procedures to replace it, or is it a simple unscrew out and screw new one in.
Should the transmission be in any paticular gear?

 

Nah, doesn't matter, just unscrew it and screw the new one in. It's a 19mm or 3/4" iirc.

 

Thanks..
Yes it was the switch. 22mm deep socket. The switch is a round button roller actuation, looks like a ball bearing.
Ah yes, on to state inspection to see what else they can find wrong. LOL

 

You're very welcome, good luck with the inspection!

 

I have the same problem.I have the new switch but I can't find the old one on the transmission?

 

I found it and changed it but still no lights.I checked the fuse.Next I will check the bulbs.

 

Im a noob here.

Any idea where this switch is located on a 1994 s-10 Blazer Auto 4dr?Any help will be greatly appreciated.