If you have voltage then you need to provide a good ground to verify fan motor is good. If, with a ground, it still is inop, I would suspect the fan power module.
Sorry, a little confused.... Could you be more specific?If you have voltage then you need to provide a good ground to verify fan motor is good. If, with a ground, it still is inop, I would suspect the fan power module.
Where would this be located? Are you talking about the dash control unit?I would suspect the fan power module.
Would the PWM be the same as the ACM? I checked the troubleshooting chart and tested the connection terminals: A (ground), C (red) and was 14v and B (grey) and was not greater than 4 volts. It's starting to look like the ACM has failed.The fan speed is controlled by PWM (Pulse Width Modulation). I think it ranges from .03v - .09v. If I remember correctly, putting 12v to it won't do anything. Don't quote me on this, but I think there are 3 wires? One = Grnd. One =12v and the other is PWM.
Funny..... My gut tells me the same thingWhen my '97 failed all signs from the FSM pointed to the ACM, but my gut told me otherwise. ACM's are very expensive and very reliable. Blower motors are not. I went with my gut and it payed off.
Where is the ACM located and what does it look like? I pulled the glove box and really didn't see anything other than the cable and air directional doors.ACM's are very expensive and very reliable. Blower motors are not.
Maybe I'm missing something and someone can chime in. Looking at the wiring diagram it appears going to the motor you have the 1) red 12v constant, 2) grey wire which appears to be grounded then going through the resistor in the ACM, and 3) black ground.The fan speed is controlled by PWM (Pulse Width Modulation). I think it ranges from .03v - .09v. If I remember correctly, putting 12v to it won't do anything. Don't quote me on this, but I think there are 3 wires? One = Grnd. One =12v and the other is PWM.
I did, very good write up and informative. Thanks for all of the advice and tips....Go to the Tech Tips section and read my tutorial on changing it if you haven't already.
Roger that.I completed the job from start to finish in about an hour and 45 minutes including a 5 minute or so break 3 or 4 times to give my back a chance to recover. My back just can't take it anymore. Used too, I could spend hours under the hood wrenching.