heat / Ac control fan --- only runs on high ---

[weg240sx]

Ok I have a 1995 S14, well a week ago the heat/ac fan started to only run in position #4. 1,2,3 did not work. So I thought it was the fan control switch, I found a used control unit and replaced the one that I had. Everything pluged in perfectly, the only problem is that the heat/ac fan only works on position #4. I must be missing something, is there a fuse inbetween the switch and the motor; is the motor bad? Where cna I look and has anyone else had this problem?

[positron1]

Sounds like the typical bad blower motor sensor. Don't exactly know where it is on a S14 but on a S13 it's behind the glovebox on the blower.Blower motor resistor/sensor.

[weg240sx]

I think that you are right. I talked with the Nissan dealer and that is what they think it is too. I am going to pick one up tomorrow. It steps down the voltage to the motor and lets it run at different speeds. thanks for the info and I will let you know how it turns out.

[ricebike]

this is confirmed:

i had the same problem when i purchased a pre-owned nissan quest...

pulled it out and examined the open circuit board... the metal was missing to make a complete circuit & previous owner did a terrible job at trying to solder them back together...

~$34 at a local autozone & i was back in business

[0wn3r]

blower motor resistor.

just replaced mine a couple weeks ago...i think it was $28 at auto zone. it should look like a flat wireless card that you'd put into a laptop.

[weg240sx]

Replaced the blower motor resister and everything worked perfectly. From what I underestand is that this card steps down the 12 volts going to the blower motor. So if the card fails then the motor only gets 12 volts and runs on high. With the card installed then the voltage is steped down to give you speeds 1-3 instead of just 4. Anyway, the overall cost was just under $24.00 at the Nissan dealer. It installs just behind the glove box at the base of the blower motor housing.