HVAC blower motor resistor

Hello All,
‘03 F-150...blower motor quit working. Fuse in power distribution box not blown,
no fuse I can find in fuse block inside truck is on this circuit (at least according to
the owners manual and Chiltons manual). I removed the blower motor resistor
the small thermal fuse is not burned and the two wires to it are not burned through.
All other wires are not burned through. Ohmed the terminals, as directed by the
Chiltons manual. Two of the readings didn’t match the ohms value it should have
(they were lower than Chiltons said they should be. Given the notoriety of Chiltons
manuals mislabeling or typos, should I trust their suggested ohms readings?

Take that Chilton's book and use it to start a BBQ. Order a dealer Ford repair DVD online for $15.95. #105 blower 40 amp relay is what I would have swapped out, along with checking power into it switching power and ground. That's where I'd go next.

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Originally Posted by Moosee1955

Take that Chilton's book and use it to start a BBQ. Order a dealer Ford repair DVD online for $15.95. #105 blower 40 amp relay is what I would have swapped out, along with checking power into it switching power and ground. That's where I'd go next.

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Thank you for replying!

Roger that Cjiltons fire starting book. 🤣

The #105 40 Amp is a fuse in my power distribution box (under hood) and it looks like it is good (the thin wire is not melted). Could not find a HVAC fuse listed in owners manual in the fuse block inside the cab. Check #105 socket for volts after taking the fuse out? Will try that next. If I do have voltage at those socket terminals...next step?

Again, thank you for your help!

Hello again...where do I order the official Ford Repair manual for $ 20.00? Parts stores only sell the chiltons or haynes.
Do I go to a dealer ship and order through their parts department?

Dave their available through eBay. As far as just looking at a fuse is a no no! You always use a continuity light or a volt/ohm meter, and probe both sides of fuse. I've seen fuses that were hot on one side but dead on other. I can't tell you how many members on my expedition forum chased their tail for weeks, just to find someone prior had tapped into that circuit for an alarm, or stereo, and screwed up the item they were trying to diagnose.

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I just reread your first post, we have 2 members over on the Expedition forum with same problem. Your vehicle uses a module that replaced the resistor on other vehicles. Locate it, and test and if necessary replace with a Ford part. The Chinese knockoffs don't work. You can pull the plug to the blower and test for power going to it. Also can jump the motor with power/ground to see if it fires up!

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Ok...will look on ebay or amazon for that dealer repair manual!
Additionally...will pull the “fuse” from the 105 cavity and ohms check. I am also gonna hotwire the blower motor to the battery to see if it runs. IF it does...Gonna install a rocker switch and go with that. AC compressor died years ago. HOWEVER..I need air movement to defrost windshield!

If you go the rocker switch, be sure it's 30-40 amp fused. Don't want a fire ruining that pretty truck!

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My truck has the actual resistor. Thermal fuse is not melted. All wires intact (no wires rusted or burned through). RI will install a fuse holder, 40 amp, as specified if I put a rocker switch in.