06 Pacifica, automatic climate control; Fan blows on high, controls will not change the speed.
I replaced the resistor part behind the glove box, no change.
I replaced the climate control (the head unit), no change.
I plugged a new fan motor into the resistor relay and it also only runs on high and is not affected by the controls.
I was going to change out the motor, but it seems like the test shows it won't make any difference.
Any help would be appreciated.

 

does it run on high even when the car is off or the ac control head is turned off?

 

Fan stays on high when a/c is turned off, but it does stop when car is turned off at the key.

 

Also tried a second new resistor but it did the same.

 

did the reset on the head unit power+recycle; it went through its paces but nothing changed. Also unhooked the battery to try and clear any codes, again no change.
Just hooked up the new motor again and it still only blows high, same as the one in the car. I also swapped the relays and fuses under the hood with no impact.
Really stuck on what else to try.

 

you have a shorted wire do you have a volt meter and or ohm meter?

 

yes, I have meters. But, I really haven't ever been able to figure anything out with them.
What should I check and what actions will I need to take if I find something?

Thanks for the reply, I am really stuck (and old).

 

0at the blower motor resistor make sure there are not any burnt wires at the connector first.
Second black and orange wire has a good ground. ohm meter to ground when connector is disconnected low resistance.
third bark blue lite blue wire. for this remove the ac control head disconnect it make sure there is no short to ground or power on that wire. or to any other wire

 

Ppritchard, I am attaching pertinent tech info from the most excellent factory repair manual (includes info for Manual & Automatic AC, sounds like you have Auto). Your AC blower repair will require some objective detective work, but it sounds like you are up to the task. Good luck, if any questions as you proceed please post. Got to keep those old Pacs rolling!

 

djetelina, Yes we do! 242,000 miles, bought her new in Dec 05.

The AC Hardware Printout is a great tool for understanding the entire system. Thanks for the info.

The Wiring section's Troubleshooting section does not address my issue:
1. Fan Blows High regardless of setting
2. Controls do not lower the fan speed.
3. Fan does not turn off if a/c is turned off.

I am also puzzled that when I attach a New Fan Motor, the same one speed issue continues.
Everything I read says "Bad Resistor", but I have tried two different New Dorman versions with zero change.

Any thoughts???

Thanks again.