Hi Folks, I have a 2014 535i x-Drive where my HVAC system just stopped working the other day. I've pulled the blower motor and removed the resistor but wondering if there's an easy way to bench test either of them or test the wires connecting to the unit (eg, is the blower even getting power, OHM specs, etc). Also, stupidly, I haven't checked the fuse(s) yet. Any thoughts on where I can get the fuse mapping? Thanks.
To clarify, only the blower stopped working? Or the whole A/C control panel is dead and not working?
ASE and BMW Master Certified Technician
Thanks for the reply, the A/C control panel has power and "works" as far as accepting input to change zones, settings etc, but the blower does nothing
Should have replaced the blower motor at the same time as the regulator. Or at least tested it. You can test it by putting 12v directly to the blower motor wires. Black is ground, red is power.
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ASE and BMW Master Certified Technician
Sorry, I wasn't clear. I have not replaced anything yet. Was trying to test both the blower and the regulator. Further, wanted to test the harness connecting to the assembly if that's possible. I'll test the blower tonight. Thanks for the help
Sorry, I wasn't clear. I have not replaced anything yet. Was trying to test both the blower and the regulator. Further, wanted to test the harness connecting to the assembly if that's possible. I'll test the blower tonight. Thanks for the help
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Tested the blower. Works fine. Tested the wiring harness in the car (brown and white/red) wires I believe. With the car running and blower on full I get 14 volts or so on white/red and 0 on what's grounded.
https://youtu.be/FtacsFs3_9Q
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Just because blower motor is working doesn’t mean it’s good. Check the impedance and look for burning smell. See the above video. Mine failed but it worked for a long time before actually giving up.
Also check for fuses in back trunk on top of battery module.
Also check the resister for the blower motor.
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Thanks for the post. There's no burning smell coming from the vents and the motor smells fine when running via a spare car battery. I Checked the motor and the impedance is fine. I suspect the resistor, but not sure how to check that. Thoughts?
Buy one and replace it.
ASE and BMW Master Certified Technician
Tested the impedance of the resistor when plugged back into the blower. The Power (red wire) shows open (non-zero) so perhaps that's the confirmation it's bad. Anyhow, I've ordered a new one and will report back.
Update. Finally received the resistor I ordered (seemed to be very hard to find with lots of out of stock). Anyway, purchased a new one from eBay and it worked!! Was really happy with that result. Appreciate very much everyone's help here.
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