Started car and pushed a/c button and nothing came on. I hear the normal click sound you hear right before a/c turns on but nothing after that. A/C had been working fine before this. There's absolutely no airflow with all push buttons, no fan motor noise, no air flow in all vents. I purchased the car 4 months ago with 168k miles on it. Car has been perfect until this happened. 1989 420SEL...Please help. Thank you!

You should check the blower motor fuse. Its near the brake booster, in its own little case.


If the fuse is OK then theres a good possibility that the blower motor and/or blower motor regulator have failed.

Blower motor is bout $80-90. Regulator is $150-$190. I think.

This can be checked a number of ways. If the fuse was OK, I'd check the voltage going to the regulator. It will vary from 0-7V depending on speed command.

If that was Ok, I'd pull the blower motor, feel it out, it the bearings dont feel seized, id throw 12V to it and see if it spins. If it spins fine and doesnt make noise. Then I'd replace the regulator.

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82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

I'm heading out of town for a fews days but will check fuse etc when I get back. Thanks again!

I was able to check the blower motor fuse before I left town. It was completely snapped in half! Wow.....you're good! Thank you!!!