I'm working on a 1975 coupe with AC and the heater/wipers do not work.

Heater:
I checked the fuse and it's okay. I checked to see if power was coming off the heater switch with a test light and I am getting power, except on high. Next I pulled the blower resistor and one of the coils is gone. I checked with a test light the plug to the resistor as the heater switch was moved between the speeds, all worked except on high. I then checked the relay. The orange wire was in the wrong position, as checked by a schematic. The orange wire gets power but no others lit with a test light. I ordered a new resistor and relay.





Wiper Motor:
I checked the fuse and it's okay. I checked with a test light and I am getting power to the yellow and light blue wire. There is a black wire also in the harness but in the schematic it shows it should be a Light Green, no power to this wire.


I read on a thread last night, and confirmed by looking at the schematic today, that if the ground wire is not hooked to the starter that the heater/wiper would not work. If you look at the picture of the starter the ground goes right to the starter housing and there is a Dark Blue and Orange wire, and there is a 3rd wire but I can not figure out what color it is, to the starter for a positive. And there is a terminal that is not used on the starter. The Dark Blue wire is not hooked up to anything, as seen in the picture.









If you guys could shed some light on my issue that would be great. Thanks

Your year may have a i line 30 amp fuse under the left fender near the master cylinder, see if it's good.

petes74ttop: Yes I checked the 30amp fuse and it is good.

On the starter:
You should have a HEI distributor so you will not have a wire on the "R" terminal.
http://www.vetteprojects.com/bmv/mis...tte%201975.pdf

The ground for the heater & wiper motor goes to a starter or bell housing bolt, your connection on the solenoid could be OK but double check it.

You might get your answer here at post 6.
http://forums.corvetteforum.com/c3-t...an-blower.html