Air Conditioner problem - do I need a run capacitor ?

May 21, 2009 6 Replies

I have an older a/c unit. Last year it was functioning just fine. This year, as it's running, the lights in the house dim on and off, just slightly.



This didn't happen while the furnace was running so I ruled out the blower motor.



I suspect that this is caused by a/c motor run capacitor. Does this make sense ?



I have little electrical experience but I did stay at Holiday Inn Express a few times ;)



The guys at

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helped me fix mine last year.

Capacitor @ 2/$5.00 VS the $275.00 quote for a new motor

Why not ?

AC fan motor doesn't draw all that much juice. Not enough to dim the lights. If the compressor capacitor went bad, the AC wouldn't cool.

I just had the same problem, including the lights dimming on and off! It was the capacitor...After we replaced, the unit runs fine!

Reality can be so much different, I guess. I can imagine a compressor run cap being bad, and causing the lights to dim. Central AC compressors take a lot of amps.

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