78Vette-SA

Just installed a new heater core on my friends 81. Before doing so, the blower motor didn't work at all. I took the conbtacts off the switches and cleaned everything up. I now have the switch working. But it does not work on high. Only low and medium.

On my 78 the high will not work if the defroster is on. So there is probably somethign in this ciruit preventing it from coming on is my guess.

Currently the dash is apart and the cluster is out (see other post on cluster problem). I'm just turning the key to the on position, not starting the car. The heater hoses are not hooked up yet.

Open to suggestions on how to diagnose the problem.

Thanks

rcastor426

at last someone with the same problem as me!!! i have my entire interrior out of the car trying to figure this problem out. i have found that if i remove the relay for the rear defroster, the heater works on high, when every thing is hooked up, it comes on for about half a second and then is off. i am on my way to pick up a blower motor cut off relay, i found that the black wire coming out of the defroster goes up and that is were they meet. i hope it fixxes it. i will tell you how it goes in an hour or so. and my car is a 78

rcastor426

nope, the relay did not fix my problem????? something else i noticed is that when i turn my fan on high, it makes the rear defroster,come on??? does this happen in yours.