[Richard]

Another "fix" to try before replacing the compressor if the start cap doesn't do it is to ADD a hard start cap. A hard start cap is an additional capacitor to get the motor turning. The difference is the hard start cap has a built in timer so that it takes itself out of the circuit after a few seconds to keep from frying the motor. I would recommend a supco 4 or 5 for the compressor. Any ac supply place will have them or amazon

[smagown]

Unhook the wires to the compressor and flip the breaker on to eliminate a direct short some place other than the compressor. If it doesn't trip the problem may be in the wiring instead of the compressor..

[folivier]

Update: I did Steve's suggestion and pulled the wires to the #2 compressor, breaker didn't trip, outdoor fan switches to HI and runs OK. So the fan motor should be OK, and the board should be OK also?
Put in a new 20 amp breaker.
Changed the 45mF capacitor (tested the old one and it looks ok) and the breaker still trips. The ac voltage when switch to HI drops from 120 to 108 then breaker trips.
The amps (using clamp-on ammeter and MAX reading function) with new capacitor were: 42.6; 13.4; 28.0; 24.7; and breaker tripped each time.
Any other suggestions?
I haven't pulled the unit out of the coach yet. If I do will I be able to determine anything?
Can I test if the compressor is shorted from the purple or yellow wires that connect to the board?

[Richard]

Yes you can test the compressor to see if its shorted. Google around and you will find a formula formohmingmthe three leads. You should find guidance on what the ohms should be between all three leads.

Btw, I love reading posts on the tablet but I hate typing on this contraption

[Richard]

Forrest

Sorry. I am dumber than a rock. Measure the ohms between the motor leads and ground. That should be infinity for all three. Now measure the ohms between the three leads. IIRC you should see around 20 ohms for two of the legs and a coupl of ohms for the last one. Here is my dumb moment, measure the sAme readings for the ok compressor to get a comparison. Duh huh on my part.

[folivier]

Here's what I did yesterday, checked the wires from control board to compressor at plug-
Compressor #1 (working compressor)
white to ground. Infinity ohms
Black to grd. Infinity

Compressor #2
Purple to grd. 9.8 ohms
Yellow to grd. 10.6 ohms
Purple to yellow 1.2 ohms

Looks like #2 compressor is bad?
Still haven't pulled unit out yet. Someone on 'other forum' recently changed a compressor, I've pm'ed him for info but haven't heard back yet.
Anyone have info on the compressor?

[encantotom]

on a fridge you check across the 3 compressor terminals. remember forest?

they are in series. so the two legs add up to the 3rd measurment. which to me looks like compressor is adding up right, though they are usually about the same on each leg. i think when you and i did the fridge compressor it was like 4 ohms and 6 ohms and 10 ohms.

so i dont understand what the compressor one is measuring. that is if you measured across the 3 term on the compressor

tom

[Richard]

I kind of assumed that Forrest did not did measure the common

[Express1]

Yeah, Richard, I was not sure where you were headed with that diagnoses?

[folivier]

Had a local a/c guy come and pull the unit. He checked the #2 compressor and it is shorted. So I had him quote me on replacing it. Ready??
$1800 for the compressor and $600 to install. I took a picture of the tag and can find it for $380
So I had him clean the coils and put it back together. Called Cresley and he is working on an estimate. Rather have them do it when we go to Miami next month.