AC Blower Motor Issue

[1der]

On the off chance it might be a bad ground, you might want run a wire to test for that as well.

[audisnapr]

Good point, Ray. Thanks.

[Viva]

I'm not an expert on the vacuum system, but my understanding is that when it fails, the HVAC fan always defaults to "defrost" (not "floor"). This is said to be a safety thing.

I think I have some (smaller?) vacuum leak because when I'm really pounding up a hill my vent will occasionally switch to defrost, and then go back to wherever I had it set after the engine strain is over. I think this is because I'm using all the available vacuum to chug up the hill, and the leak means there is not as much available as there should be.

Anyway, I have never read anything wherein a vacuum leak would make it default to "floor" as yours did, although maybe I just haven't read enough yet.

[audisnapr]

Originally Posted by Viva

I'm not an expert on the vacuum system, but my understanding is that when it fails, the HVAC fan always defaults to "defrost" (not "floor"). This is said to be a safety thing.

I think I have some (smaller?) vacuum leak because when I'm really pounding up a hill my vent will occasionally switch to defrost, and then go back to wherever I had it set after the engine strain is over. I think this is because I'm using all the available vacuum to chug up the hill, and the leak means there is not as much available as there should be.

Anyway, I have never read anything wherein a vacuum leak would make it default to "floor" as yours did, although maybe I just haven't read enough yet.

Mine only defaulted to floor once, then never worked again.

BTW, my 5.8 gasser will go to floor or defrost mode (I can't remember which) on an uphill pull as well. I always just assumed it was a way for the engine to cut the AC when it needed more power - haha

[daveb]

I wouldn't be surprised that if the motor can be turned (spun) it would probably start running again but they almost always will stop and fail again once turned off. Don't let that throw you off if it does all of a sudden start running again.

[JWA]

Originally Posted by 1der

On the off chance it might be a bad ground, you might want run a wire to test for that as well.

I believe the motor is grounded through its metal casing and doesn't have a dedicated ground connection. However it wouldn't be a bad idea running an extra ground wire from one of the case attaching screws to part of the body, perhaps doubling up on another close-by ground connection.

[audisnapr]

Originally Posted by JWA

I believe the motor is grounded through its metal casing and doesn't have a dedicated ground connection. However it wouldn't be a bad idea running an extra ground wire from one of the case attaching screws to part of the body, perhaps doubling up on another close-by ground connection.

More confused now that I started looking into this further and may have wasted $70 on a new motor.

There is one connection to the motor - that connection has a red wire with faint green stripe and a red wire with a black stripe.

When the AC dial is on any other mode than off, the red wire with green stripe shows power (via light meter). The red wire with black stripe is what, a secondary power source for high speed? Or is that the ground?

As far as I can tell the screws that go into the motor shroud attach into plastic, so I'm not sure where the ground comes from. Furthermore, theres a neoprene style gasket between the motor and the van.

Also, I tried to verify that the new motor works by connecting it to the factor plug, but it does nothing.

Where is the ground on this setup?

[audisnapr]

Nm, problem solved. It was the relay.