Forum Discussion

Damdifino's avatar
Damdifino
Explorer
Sep 06, 2018

Turn on my A/C and it just goes hummmm...

I've been having A/C anomalies this summer, which I thought I'd fixed. First, it tripped the breaker, so I cleaned the coils, changed the circuit breaker, and it ran good for a couple of weeks. But now, I turn it on and it just hums, like it's struggling to start up. What should I look at?

34 Replies

  • ScottG wrote:
    Exactly what mine did when the start cap died.


    Yup. You not getting enough help from the capacitor. You'll need an soft start capacitor. It used to be you'll need an hard start capacitor but the newer soft are a little easier on the motor windings. Older ac usually needs some extra help because they wear out and need more wattage to get going. Just get one and hook it up piggy back to the original capacitor. Look up on YouTube/Google search about how to hook one up on an RV ac.
    https://www.loveyourrv.com/installing-hard-start-capacitor-into-my-rv-air-conditioner/
    Here's one on hard start.

    If one of those original caps is bulging then it need to be replaced first. Then try ac. If problem not solved, then add soft start.
  • I had a similar issue with my Dometic ac, ended up being a "run capacitor". Found one on Amazon for $10 shipped to my door. Working great now.
    Just put your model number into one of the online parts places and find the part number.
    Shop around with that part number, Amazon, Ebay etc. You will find a good price that way.