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Problem: Lights in our home dim when the AC starts. What could be the problem?

Problem: I’ve purchased from you before, and love your website.  I remember reading somewhere on your sight about lights dimming on A/C start-up.  My lights are starting to dim more this year and last vs. when I put in my Bryant unit about 5 years ago.  Is this the starter capacitor, you think?  Where on your sight do you sell the replacements if this would be the main culprit?

Answer: Thanks for your continued interest and support in our web site! Lights dimming on air conditioner start up can be caused by several things:
1: Circuit breaker going bad. See if you breaker is getting warm by touching the outside of the breaker after your air conditioner has run for a while. If the breaker is warm then you have arcing inside the breaker and need a new breaker.
2. Loose wiring. After turning off the power and checking to make sure the power is off with a volt meter. Make sure all wire connections are good and tight from the breaker through the air conditioners contactor to the Compressor terminal wires. Loose connections cause high amperage and can cause lights to dim.
3. Capacitors going bad or getting weak. Test capacitors with a capacitor tester or if you do not have a capacitor tester take you capacitor to an appliance repair parts store and see it they will test the capacitor for you.
4. Compressor getting tight. Compressors that are worn can become tight and hard to start. A compressor hard start booster might help this situation. We sell the compressor hard start booster the Supco SPP6 on the following page:
5. Low voltage from your house. You should be getting at least 220 to 245 volts to your air conditioner. Call your electric company supplier or a licensed electrician if you voltage is low in your home.  Loose electrical connections coming in from your electric pole to your indoor electrical circuit breaker box can cause the lights to dim. Connections might need to be tightened up. I would recommend calling an electrician to troubleshoot this problem. Below we have a real good YouTube informative video made by Grayfurnaceman that shows why a breaker keeps kicking off. Thanks to Grayfurnaceman for making this informative video! This problem would also cause the lights in your home to dim.

I have tried to cover a few of the things that can cause lights to dim when your air conditioner comes on. If you have any other questions please feel free to email us at: or comment in the comments section below.
Thanks for the opportunity to do business with you! We would love to have your business! Steve & Barbara Arnold

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