Why wouldn't a blower motor work?

[glucklich21]

So I've gone through 3 blower motors and all 3 have had the same problem. They work inconsistently. I've replace the resistor 4 times, one time being a new one, cleaned all the connections, checked all the switches, fuses, etc, but to no avail. It's completing a circuit the best I can tell, ie: the recirculating button lights up for a quick second and the fan spins when you turn the ignition on. After that nothing. It use to only happen every now and then, but now it won't work at all hence motor #3.


Any ideas?

I'm hearing a relay kick off when it looses power, that I can hear.

[Quadrajet]

In general I'll make the comment on the assumption there is something wrong in the AC circuit. Two of my cars the AC didn't work because the pressure switch was bad, but didn't go any further, due to the fact that it doesn't get near as hot here as where you are.

Hopefully someone with more info can enlighten you on where to look first.

[u3b3rg33k]

Have you tested the fans outside of the car (known good power)? I'm assuming yes, and that you have a vehicle wiring problem.

[ccrelan]

I am very interested in this thread as well. I have pretty much done the same exact thing and currently have 3 blower motors, numberous resistors, and still have nothing. At first, it was just the resistor. I replaced with a working one and everything was fine. However, I now have nothing. It was so frustrating that I pretty much took a time out with the car. It is worse because I am fixing the heater core and don't want to do it all until I have the blower working!

['e30love']

Interested in info as well my blower motor only runs as I'm turning the car on when I'm on the starter the when the car turns on blower motor shuts off

[DaveSmed]

...the recirculating button lights up for a quick second and the fan spins when you turn the ignition on....

I'm hearing a relay kick off when it looses power, that I can hear.

Interested in info as well my blower motor only runs as I'm turning the car on when I'm on the starter the when the car turns on blower motor shuts off

Huge hints right there. Do you also happen to be having problems with your power windows, sunroof and power mirrors too?

['e30love']

Huge hints right there. Do you also happen to be having problems with your power windows, sunroof and power mirrors too?

Windows work sunrof works side mirrors stopped working, cluster doesn't work occasionally the speculated tries to work. I'll be swapping out my dah next weekend I'm prepared to see an electrical mess and be prepared for questions and pictures

['e30love']

Windows and sunroof work. Mirrors stopped working and cluster and obc don't work.
When I turn on the car the blower motor works, when the car actually turns on the blower motor stops working.

My car very rarely but it does it'll turn off when I'm driving and a couple times it turned back on. Could something be loose in the ignition when you insert the key that could cut it off like move the key just enough to turn off the car?

[DaveSmed]

Is fuse 10 blown, causing the dead cluster?

Fuse 10 powers unloader relay K7, which in turn supplies power to fuses 19 and 20, which among other things supply the blower motor and power mirrors.

['e30love']

Pretty sure I checked and no blown fuses I'll check again I doubt it thou

[DaveSmed]

Visually is not enough. If all your headlights work, swap fuse 10 with fuse 1. The element could have a small crack.

['e30love']

Ok I'll try that when i get home

[glucklich21]

So I just took a volt meter to fuse #'s 1, 10, 24 (as a visual that connection was being made with the voltmeter), and 20. My control fuse, #24 was the only one with power.

So I'll throw in one of my spare relays and see.

[glucklich21]

Switched the relay with the known working one from my fogs. Still nothing.

Edit: I should point out I've noticed my mirrors have stopped working as of today. OBC is still kicking as is the cluster.

[DaveSmed]

Your car's windows working correctly?

Also, to further clarify, fuse 1 would have nothing to do with either problem, it's just a convenient 7.5A fuse to swap with. :)

Fuse 10 controls a whole load of things that are tied to the ignition, most obvious is the gauge cluster. If that works, it is a safe assumption that relay is getting power.

Fuses 19 and 20 are the ones controlled by the relay.

As you tested, Fuse 1 should only show power with the high beams on, fuse 10 with the ignition on, and 20 with the ignition on and the car not cranking.

The unloader relays receive +12v from the ignition, and ground out through the starter windings.