Within the past few days, my front HVAC fan controls are not working properly. When the fan setting is on Low, 2 or 3, the fan barely blows anything. As soon as I go to High, the fan kicks on full blast. My rear controls work perfectly fine from both the front and from the rear overhead controls. Is this a sign that my fan setting switch has gone bad and needs replaced? This is happening regardless of what function I have selected (A/C, heat, defrost, etc.). Thanks for any help.

 

Do you have dials, or the electronic climate control?

 

I have the dials. Fan control left side, temperature in middle, and the heat, A/C, defrost, vent, etc on the right.

 

In that case, replace the blower motor resistor.

 

Any idea where it is located and how hard is it to replace?

 

Here's a video...

YouTube - ‪2001 Ford Expedition Blower Motor Resistor.avi‬‏

 

Excellent video! That is exactly what my controls are (or aren't) doing. Thanks for the info. Seems easy enough to repair.

 

alloro,

The resistor was the problem. I replaced it today in 10 minutes total and the fan controls work great now. Thanks again for your help. I have my A/C again!!!!!

 

Ok, more problems have arose. Rear controls still work fine. I have lost all front controls. I drive a Subaru for my daily 60 mile commute during the week, so the Expedition sits during the week, but gets driven on the weekends.

Last weekend and early last week, the front controls worked fine, blowing ice cold A/C. Saturday morning, I had barely anything coming out the front vents with the front fan control on any of the 4 settings. I seemed to get a bit more flow when the setting was on HIGH, so I left it there all weekend with the rear A/C handling cooling the interior. Sunday afternoon, while driving around, the airflow from the front vents stopped and about 15 seconds later, I smell an electrical burning odor. It got worse within a few seconds, so quickly shut off the front HVAC controls, and the smell, while lingering, didn't get any worse. When I got home and tried to diagnose the problem, as soon as I put the front fan control to HIGH, the interior lights got really dim and I could hear the alternator lugging. I turned the system off and disconnected the plug from the blower motor resistor, thinking it may have gone bad again. Turned the fan back to 3 and truck and lights ran fine. Tried HIGH again, and same issue - lights dim, alternator lugging. I pulled the entire control assembly out of my dash to see if I could find any burnt wires or melted plastic, but could see nothing. Could it be the front fan switch went bad? I am not good with a resistance meter, but have an electrical gu-ru at work that is who could try testing the switch. I'm at my witts end here. Any and all help is appreciated. Thanks!!!

 

Apology accepted!

 

You could be having an issue with the high speed blower relay, or the circuit coming off it, shorting out. It's under the driver side dash, to the right of the steering column, and it is bundled with the turn signal flasher unit. So if you turn on the TS or 4-ways and listen for the clicking, you should find it in no time.

 

Excellent description on how to find the relay! I managed to locate it, small cube relay next to a larger blue relay, which feels to be the T/S relay. Everything appears and feels secure, although the relay didn't seem to want to budge. The cover to both relays had a faint burnt electrical odor to it, but nothing like the smell I had yesterday. I'm wondering if the socket for the relay melted and isn't allowing the relay to come out. I'm going to try and take the trim panel off tomorrow after work to get better access to the relay from above. Damn mosquitoes were out in force tonight and were taking great pleasure in attacking me.

 

You're correct, the larger one, and sometimes it's blue, is the flasher unit. The use of a small screwdriver to gentle pry around the relay, might be in order to aid in the removal of the relay.

 

LOL. I know, I know. But, sure makes life easier putting $40 into a gas tank instead of $120 to get me through 5 days of commuting.

 

I gave my HVAC controls to the electrical genius at work for him to look at. He could find nothing wrong with the switches, so I am ruling them out. He has many, many years experience rebuilding automotive motors and alternators. I ran him through what happened and he is almost 100% certain my blower motor is shot. Some of the things I was describing to him led his diagnosis to the motor itself. Going to try and pull it out tonight so he can bench test it tomorrow. What a project this is turning out to be......