Strange grinding noise in cab

Got a 94 chevy p/u and when the ignition is turned on or when it is shut off, a noise that sounds like an electrical actuator is trying to open/close occurs. Can't hear it when the truck is running though. The noise is coming from the lower dash area close to the blower motor, but it is not that. There's something within the black a/c duct work that is causing the noise but I don't know what's all in there. The a/c blows cold and everything appears to operate normally. Any help would be much appreciated.

thanks......

Got a 94 chevy p/u and when the ignition is turned on or when it is shut off, a noise that sounds like an electrical actuator is trying to open/close occurs. Can't hear it when the truck is running though. The noise is coming from the lower dash area close to the blower motor, but it is not that. There's something within the black a/c duct work that is causing the noise but I don't know what's all in there. The a/c blows cold and everything appears to operate normally. Any help would be much appreciated.

thanks......

this is usually the air damper ac control in the duct work ..they all fail this way very common ..

Thanks for the quick reply. After reviewing a picture in LMC the noise appears to be coming from exactly where the air damper inlet actuator is. I didn't even know there were two within the system. I'll buy one and replace it this weekend.

Noise was the air recirculation actuator up behind the glove box. I can say that after having this truck 17 years, that if I have to change this part again I'll sell it first. Pain in the ass to say the least....but it was a good fix.

thanks...

Noise was the air recirculation actuator up behind the glove box. I can say that after having this truck 17 years, that if I have to change this part again I'll sell it first. Pain in the ass to say the least....but it was a good fix.

thanks...


it won't be much longer that this will sit in the back yard with the other dead vehicles.