Cliff's notes-Front blower isn't working. Rear is fine. Fuses are fine, 12.2v at the plug when I turn the switch to vent. Swapped the motor and solenoid. Still no luck. Jumped the old motor off the battery-works. Jumped the new motor (installed) off the battery-works. Tested to make sure I wasn't crazy. 12.2v. Plugged it back in. Doesn't work at any speed. I did a search but didn't find an answer. I am dumbfounded.

Greetings. I bought a 2001 Excursion 7.3 2wd a few weeks ago. It has 430k miles on it. It has been well maintained and is very clean. But it's testing me. I bought it in SC, and drove it to Indiana. A mile down the road, the speedometer quit working. A quick google led me to believe that is was the speed sensor. A stop in Autozone and some borrowed tools and I was on the road again. Didn't fix the problem, but it would shift into OD at least. Got it to TN and stopped for fuel. Turned it back on and had a battery light. I had downloaded the torque app and bought a bluetooth dongle for it, so I plugged it in. 12.9v. Not great, but not terrible. Proceeded to watch it dwindle to about 6v just outside of Knoxville at 10pm where it shut down. Had it towed to an Advance Auto and spent the night in it. Swapped out the alternator in the parking lot the next morning with more borrowed tools, and I was on my way again. New alternator even fixed the speedometer. Got it home, and the front blower quit working on it. Checked the fuses. They seem fine. Replaced the fan and the solenoid but still no luck. So I thought I'd see if the wisdom here could shed some light. Like I said, it's definitely testing me. I think he's mad that I took him from his owners after 22 years. They ordered it. It even has a VHS player. Great info here. I've been lurking thru the forum for a while when I decided to buy one.

 

Check the resistor plug spades for poor connection, like burnt or corroded spades. I think you are referring to the resistor on the blower box as the solenoid..

 

By solenoid do you mean the blower resistor?

 

I just checked it, and I did change the blower motor resistor. It included a new pigtail, but I didn't really want to cut and splice it. Maybe I should? Could I just hit it with some contact cleaner? And is it weird that I'm getting voltage at the fan, but the fan doesn't work? Or would you expect that if the blower motor resistor pigtail is bad.

 

The resistor cannot cause a loss of ALL blower speeds (HIGH bypasses it completely) assuming everything else is wired correctly and working.
No, I'd expect that if its ground circuit was open. Since you do have power at one of the terminals, that does mean the blower motor relay and its controls are working. BTW, did you measure that voltage with the motor connected or disconnected? If it was disconnected, connect the motor and backprobe both wires with the system turned on and report the voltage readings for both wires at the motor connector.

Refer to schematic below for following:

I suspect that the OB/BK wire is open between the blower motor and splice S152. Or, you have multiple faults now, Multiple faults would include and open resistor or its ground G108 plus a open speed selector switch or its ground G201.

 

That is probably above my ability. I just kept messing with it. The blower eventually started working. It coincidently started running after I turned the mode selector switch to the right towards defrost and not a/c. I had done that before though. It works in all modes now. I have been waiting for it to fail again, but so far so good. I really don't like intermittent electrical problems, but this one has stayed away for a few days. And I have a spare blower motor in case the new one fails.