Blower Motor or Blowe Motor Control Module/Resistor??

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not on the rug
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Blower Motor or Blowe Motor Control Module/Resistor??

Postby not on the rug » Fri Feb 09, 2018 9:38 am

How can I tell which one went bad without replacing each and testing them?


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smj999smj
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Postby smj999smj » Sat Feb 10, 2018 7:04 am

Well, you really can't tell if any part is bad without testing them or doing the diagnostics to isolate said parts as the problem, except for substitution a known good part; that goes with just about any failed part, regardless of what it is.

If you have manual heating and air-conditioning, which is pretty rare, you'll have a blower resistor. If you have auto climate control, you'll have a VBC, also known as a fan blower amp or "variable blower control." When a VBC fails, it often goes to "fail-safe mode," where it has the blower fan run at full speed all of the time. If a blower resistor fails, the blower fan will usually run when set to the highest speed setting, but won't work on lower speed settings. If the blower fan doesn't work at all, that could be one of several things, from a bad blower motor, blown fuse(s), bad relay or HVAC control head or a shorted or open wire. I that case, I would first check the fuses. If the fuses are good, unplug the blower fan and check for power to it with a 12v test light (make sure the key is "on" and the HVAC system is "on." If there's power, you can run the test lamp between the two terminals of the harness connector to test for ground. If you have power and ground but the fan doesn't work, replace the blower (sometimes you can bang on the blower motor and get it to work). If there is no power or no ground, then you'll have to do some diagnostic work, including circuit checks. I would recommend referring to the factory service manual.

not on the rug
Posts: 250
Joined: Mon Jul 01, 2013 11:00 am

Postby not on the rug » Sat Feb 10, 2018 11:10 am

Thanks smj.

Yeah, its a VBC.

I went ahead and ordered the new blower. $40 from rock auto. Gonna pull it apart and replace it. I'll test the current 1st, but its more likely to be the blower.

I didn't order the VBC yet. I did a little more googling after I posted and it seemed to be pointing to the blower. The thing just flat out wasn't blowing air. Should be here Tuesday and I'll try to get to it wednesday afternoon (weather permitting). If not, it will have to wait until next weekend

I'll keep this thread updated as I go


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