Blower motor resistor
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2nd Gear
Joined: Jul 2025
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Blower motor resistor
I’ve replaced the resistor twice in the last two months- I thought maybe the first part I bought was a lemon, the new also does not work… only blows on 4. Could it be the switch? Relays and fuses look good.
Tuned
Joined: Oct 2013
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I would suspect poor quality of the new resistors or the blower motor being defective and drawing too much current before I would suspect the switch. If the blower motor is drawing more current than it is supposed to, that will cause the resistors to generate more heat than they are supposed to and thus burn out quickly. All the switch does is switch which resistors (or none at all) are in the circuit with the blower motor. A dead short in the switch could burn resistors but it should blow the fuse protecting the blower motor circuit first. There unfortunately isn't a published value for the current the blower motor should draw in the shop manual. The only values in the pinpoint tests are what circuits should have continuity (resistance less than 5 ohms) or no continuity (resistance greater than 10,000 ohms) when the speed selection switch is in certain positions.
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2nd Gear
Joined: Jul 2025
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Thanks for the reply. I did replace it one more time yesterday-purchased the resistor from a different place (although I’m sure they’re all made together!) works for now and it’s a lifetime warranty part, I’m also getting good at changing it out!
Fleet Mechanic
Joined: Jan 2023
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The resistor packs need good air flow across them to keep them from overheating. There is a thermal limiter in the pack that probably opens when it gets too hot. Make sure the air flow is not restricted. Maybe try running the fan briefly with the resistor pack outside the hole and see if air blows freely out of the hole.
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