Not that its an emergency but... my AC is only working on the 3 and 4, the two highest fan settings. When i turn the **** to 1 (lowest) or two it doesnt blow at all. I know, at least I have the two highest, but what could this be? IS there a separate fuse or relay for the first two settings? Im thinking switch or bad blower...

oh yeah... 2004 fx4 5.4

 

I know on older vehicles, there was a resistor pack that controlled fan speed for the blower motor. When the resistor burned out or broke, any speed selection below that point would not work, but the highest speed would always work because it bypasses the resistor pack and sends a full 12v to the fan motor.

I don't know if the newer trucks still have the resistor pack or if it's done electronically now, I tend to think its electronically tho. Check with quinton or other ford techs thay may know for sure. My best guess is that you may need a new hvac module, (that unit where your hvac control ***** are)

EDIT Just checked and you can buy just the switch from tasca for ~11 bucks or the whole module for ~120. Only problem is I don't know where the resistor is located, if its in the switch, then its a cheap fix.

 

Thanks for the info... ill wait to see if anyone knows where the resistor is.

 

You need the resistor. It is located on the heating box near the blower motor. Ford Part number 3F2Z18591AA (less than $15 on our site)

 

Oh, so these trucks still have the old style resistor pack? That's good to know, that makes it an easy and cheap fix.

 

yeah but shipping is $10, for a resistor?

 

Got the resistor shipped from rock auto for $20