Dometic 13,500. When I turn the AC on or only the fan on the coach, the breaker for the AC trips. Changed the breaker (20amp) and still the same. Cannot find anything wrong with any wiring. Fan is turning easy. Pulled the capacitors and did a check (test) I found online. They didn't check right--not sure if it's me checking or actually the capacitor.Will a bad capacitor trip a breaker? If not, where else should I check?ThanksDICK

Change the Capacitor and see if the A/C works. A bad capacitor will cause the AMP to spike on compressor start up.

Will a bad capacitor trip the breaker? Possibly yes. HOWEVER this next statement is a YES, no doubt about it.IF the bad cap is the start cap, (Some motors have only a start cap, some start and run) then the motor will never come up to speed it will remain in "Locked rotor" mode drawing way more power than it normally draws and this will.1: Trip the breaker and 2: Burn out the motor over time. So either the bad cap tripps the breaker, or it causes the motor to do it, but either way a bad cap can make the breaker go CLICK.

The only way a bad fan a capacitor would trip a breaker is if it is shorted to the case- an easy test. Just pull the wires and test for continuity between terminals and case.If it blows right away, it sounds like a dead short, or shorted fan motor. Either way, it's a matter of elimination- it could even be a short in the control box.

I have NEVER seen a capacitor cause a BREAKER to trip. Possibly to happen, but extremely remote. If you want a quick test to determine if the wiring from the breaker to the AC control is shorted. Take the 120 wires loose at the control box and stick the Black and white into a 12 gauge extension cord and run on FAN ONLY. Since you state it trips on fan only also, if the fan runs and the wall plug for the extension cord does not trip the breaker you have your answer. Since you state it does it on fan only also, it seems that the fan motor is the shorted part. You do NOT have to do the extension cord test if the breaker trips ONLY after turning the AC fan to on only if it trips all the time. Doug

Roof air questions--now need motor info 5/6/14 | Good Sam Community

Chris_Bryant
Explorer II
May 03, 2014
The only way a bad fan a capacitor would trip a breaker is if it is shorted to the case- an easy test. Just pull the wires and test for continuity between terminals and case.
If it blows right away, it sounds like a dead short, or shorted fan motor. Either way, it's a matter of elimination- it could even be a short in the control box.
wa8yxm
Explorer III
May 03, 2014
Will a bad capacitor trip the breaker? Possibly yes. HOWEVER this next statement is a YES, no doubt about it.

IF the bad cap is the start cap, (Some motors have only a start cap, some start and run) then the motor will never come up to speed it will remain in "Locked rotor" mode drawing way more power than it normally draws and this will.

1: Trip the breaker and 2: Burn out the motor over time.

So either the bad cap tripps the breaker, or it causes the motor to do it, but either way a bad cap can make the breaker go CLICK.
past-MIdirector
Explorer
May 03, 2014
Change the Capacitor and see if the A/C works. A bad capacitor will cause the AMP to spike on compressor start up.
past-MIdirector
Explorer
May 03, 2014
Change the Capacitor and see if the A/C works. A bad capacitor will cause the AMP to spike on compressor start up.

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Roof air questions--now need motor info 5/6/14

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