A/C Issues, compressor not starting
Was wondering if any of you have much experience in troubleshooting AC systems. I am working on a Coleman Fleetwood 2005 pop up trailer.
Heater, Fan and AC all on same 20 amp breaker. Outlet is located under where dining table is located. This outlet does have the T shaped plug. Currently Heater and fan both function. When you switch to AC mode, the fan speed goes down and you can smell a rubber / electrical burning smell while the compressor tries to cycle on and off ( it tries to turn on for a few seconds, then fan speed increases then decreases again as it repeats cycle). If the breaker is turned off, nothing on the unit functions.
The AC was working fine for the last two months and shore power was installed that is capable of handling 30 amps.
What I have tried:
The unit has 3 capacitors. One for AC start, one for AC run and one for heater and fan. Both the Start and Run capacitors had been recently changed within the last 3 months before we purchased the unit and they still look brand new. Odd thing is when I disconnect shore power and try to short them to release the charge, neither unit produces a spark. I replaced the start capacitor hoping that it was just bad and noticed it still will not discharge when shorted after disconnecting shore power. It's like they are not getting charged at all.
I did find a 20 amp fuse blown on the power converter and replaced it, but same issue. Checked fuse again and it is not blown, even changed to another new one, same issue.
I checked the compressor resistance from Common to Start and found it at .5 ohms. Common to Run was at .1 ohms. Run to Start was at .6 ohms from what I have been told should mean that the compressor is ok. The only thing that concerns me is I thought that the resistance from Common to Start should be much higher but I really don't know. I also checked if there was a short from Common, Start or Run to the outside of the unit (tube that comes off the side of it) and found no open circuit.
I checked the thermal switch on top of the compressor with it disconnected, and found it to be an open circuit ( no resistance). From what I understand, this is the way it is supposed to be.
Thinking that it is time to call an HVAC certified repair guy at this point as I am out of ideas unless any of you have some ideas or comments on what I have found so far.