Blower motor

Grand Prix and Grand Am, Bonneville, Montana and Transport.
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Blower motor

Unread post by Strojny » Sat May 15, 2021 9:47 am

On my Pontiac Grand Am my fan motor was working while I was driving I shut the car off about an hour later when are we started the car the blower motor would not work anymore

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Re: Blower motor

Unread post by carriedi » Sun May 16, 2021 1:49 am

If the fan isn't coming on, the first thing I would check is the fuse. It should have power on both sides of the fuse with the key in the run position. The fuse is located in the right hand fuse block behind the right side of the dash.I should be labeled HVAC BLOWER. Should be a 20A fuse. There is a high speed blower fuse in the underhood fuse block but that is only for the high speed.

If the fuse is good I would look at the blower resistor. Put the ran on the any speed except the highest speed. check the power on the dark blue wire coming from the blower resistor. The dark blue wire goes to the blower relay. If it doesn't have any power check all the other wires for power at different speeds. Yellow for low. tan for medium low. light blue for medium. purple for medium high and orange for high speed. (wires at the blower resistor connector)

If there is power at all the correct wires but nothing on the dark blue wire, then the resistor is not working. (The orange wire is for high speed only and bypasses the resistor for full on power to the relay)

Check the blower relay if everything else checks out good. the blower relay is in the underhood fuse box. it is listed as BLOWER HVAC RELAY. Sometimes the relay can get stuck. It's a sign that it is going out. Try tapping on it and see if the relay comes on. If it comes on then replace the relay. If it still doesn't come on try another relay that is the same in the fuse box. Just look for another relay with the same numbers on it. switch the relays and see if the fan works then. If the fan works get a new relay and replace the bad one. If switching the relay doesn't change anything put the relays back in the original places and check for power on the big purple wire at the fan. If you show power at the purple wire to the fan then check the black wire to the fan to see if it has a good ground.

The fan is just an electric motor. two wires, power (purple) and ground (black) When the fan gets old it will sometimes draw more amps. That could blow fuses. It might not blow them right away like a direct short but because they draw more power it could blow at any time.

My first guess would be the blower resistor though. they go out all the time. But check things out first. Don't just by parts until something fixes it. the shot gun approach sometimes gets a little spendy.

Let me know where you end up. If you get stuck somewhere in your diagnosis, let me know where you got to and I can continue to help from there.

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