Hello all! my father-in-law recently purchased an 87' corvette and I told him I would help him out with it. I have run into an issue with the A/C though, which he is adamant about getting fixed. Should be simple, but the haynes manual is pretty hard to follow and I can't seem to find a discussion on my issue, usually the blower won't turn off! So here is the breakdown of the issue. Blower motor will not turn on under any circumstances. Upon jumping a 12V supply to the blower motor itself, the fan turns on. I wouldn't say it makes a hurricane, but I can tell its blowing some air and is not totally fried. With the car off, I am measuring a constant voltage of 1.4V on the blower motor terminals. I see an inline fuse that when removed drops the voltage reading on the terminal to drop to zero or near zero, I believe there is a capacitor in the control module. Regardless of what position the fan is set on, It reads 1.4V when the car is turned on or off. I was not able to find the relay though. I thought the fuse and the relay were on the fuse box located in the passengers side, but I could not find it. I see replacement relays on rock auto but I do not see any connector with a pin-out like that. Could anyone send me pics of the location of theirs and fill me in on your two cents why i'm always getting 1.4V? I would imagine the relay terminals could be stuck or broken creating a short but I can't find it to test it. Also, I went to the junkyard today but the donor didnt have a blower control module so I do not have another to test with.

 

If you have the manual type climate controls the relay you are looking for is just inboard of the fan itself on the firewall. The fan resistor is on top of the airconditioner evaporator box. Pull the connector off the resistor and clean the contacts, same with the relay.
Make sure the climate control lever is not in the off position.

 

Thanks for the quick replies guys. I have the electronic type. I'm reading a constant 1.4V at the blower motor whether the vehicle has been off for a day or the engine is on with A/C at 10. I have no variable speed and, no speed at all. I have 1.4V from the black/red wire that runs to the blower motor, and i get 1.4v at the same colored wire where it connects to the blower control module. even when I have the BCM and the blower disconnected, I still get 1.4V on both those lines at all times. The only interrupt is the fuse holder where I believe the relay is for the manual models. Is there another connection that this black/red wire goes to? I have looked in my manual for the wiring schematics but it is nothing like what I have on my car.

 

This is my blower module. I get 11 volts on the gray/ brownish wire. The red is battery positive at 12.44V and the green beside the red gets 12.22V at fan speed 10 on Econ and fan speed 1, so I guess it’s the control box itself? I think I found a repair kit for the innards. I did take the front panel apart and cleaned the contacts which helped with the buttons working, but I guess a whole new box isn’t too bad. Upgrade time!