Blower motor

My blower for AC & heat only works on high speed. Is this a common thing? I have an 01 prerunner

 

Mine did that. Replaced it under warranty.

 

Only 2 posts. Both used to make the same thread.

 

Really two likely causes.

(1) the resistor block. The fan speed selector switch routes 12vdc to the blower through various resistors (or none for high speed). If part of this blows, you can lose some (or all) speeds except for high which would bypass the thing.

(2) the switch. Although I have a hard time imagining that multiple contacts go bad at the same time, I suppose it could happen.

One other possibility is a failure that causes some sort of over-heating, which might open the circuit around the resistor block. I am sure there must be other strange conditions that can also cause this, but 1 and 2 above have been the most common I have seen.

 

I have been experiencing this same problem lately. However it is intermittent as sometimes it works normally. Where is this resister block located? Can it be replaced by itself or is it part of a larger assembly? As for the switch, I know it is part of a module so can it be replaced by itself or must the whole module be replaced?