I've been trying to figure out how to repair the heater in the truck I just bought. I replaced the blower motor and fan to start. (Originally nothing worked as far as the heater/a/c) After replacing the motor and fan it works on low speed. From my reading I'm guessing it's the actual switch or the weird coiled resistor thing. Where is the resistor/controller located??? Do you think that would be it? It's a 1990 Toyota dlx 5 speed, 4wd, ext cab.

 

If ti was the resistor it would only work on high. Probably the switch. Also check the relay located behind the passenger kickplate.

 

Anyone have a switch for sale...they are like 35 dollars on ebay...paid less for the blower fan/motor. What does the relay look like? On a side note I replaced the door locks about an hour ago...pretty easy. I also taped off the holes with foil tape and added some dynomat I had left over since the panels had been off before and the vapor seal was missing.

 

If I was gonna sell one it'd be for $35 on Ebay Try cleaning it, most likely burned back there. And make sure it's off when starting the vehicle or it supposedly gets overcurrent.

Relay is a black 1" cube in the block above the ECU, think it's the one towards the vehicle rear. Worth a look but if you have any power to the fan it's probably not the cause.