2003 Limited explorer 237k with auto climate controls. 95 degrees out and a/c on when fan speed began going up and down a few times and then completely off. Won't work on heating as well. Rear fan works fine so I changed the resistor but still nothing. The control lights up when changed as usual but no fan.
Any ideas what to change next?

 

Try doing a self test. With key on engine off and the hvac turned off, press and release the floor & off buttons at the same time then press & release automatic . See what codes come up and google them. 888 means the control module is not the problem.

 

I never new of this test. Pretty cool! Thank 87 XLT!
Unfortunately, the left said 88,8 and the right said -188,8 which is apparently normal. I really appreciate your input!

 

You mention you changed the resistor, but since you have the auto climate control you would have a motor speed controller (solid state) rather than a resistor, which was used with the manual controls.

I'm not sure if the resistor for the manual system would physically plug in in place of the blower motor speed controller or not. Please confirm you actually installed a motor speed controller rather than a resistor block.

-Rod

 

So no trouble codes. Hers something else to check.
, there should be a blower motor fuse & relay under the hood in one of the fuse/relay boxes.

The fuse info in your owners manual will have the location. Or pop the hood & remove the lids and flip them over. Should be a diagram of fuse/relay locations. If the fuse is good try swapping the blower relay with an identical relay from the horn/wipers/windshield washer and see if the fan works.

I ws also curious about the resistor you mentioned.

 

This is what I replaced (matched exactly) purchased from NAPA. Unsure of number although it is same as a wells JA1651 and it is called a Blower motor resistor for auto climate controls - not manual.

 

My son had same thing on a Taurus. I told him to take the plug off the blower and check for voltage. He did and had 12 volts. Spun fan and it had a slight "drag" .. Tried another motor and it ran fine.......... your first statement about the speed "hunting" up and down reminded me of what he said. I told him the shaft bushings probably worn and letting armature drag the sides.

"when fan speed began going up and down a few times and then completely off."

 

Hi guys, new to the forum!

So earlier today when I left the house, the fan speed for the AC was stuck on high, so I browsed the forums, found the the resistor was probably the culprit. I popped into Oreillys got a new one (RU1266) and in 10 mins, the new one was in. I fired up the truck and now its the opposite, the high fan speed not working, but all the others are. Climate control works, until it tries to gets up to max AC, then the fan shuts down all together. Any ideas?? Its a 2009 F150 Lariat SuperCrew with the dual zone climate control
Thanks!!!