Coleman 7335(?) Series Compressor Suddenly Stopped

If it is the starter relay (actually the run relay) there will be no voltage on the compressor leads.

Most any relay capable of operating a motor at 20 amps 120 volts will work. it may not fit on the board (you may need to "Remote" it with jumper leads.
But any relay designed to run a 2 HP motor should work.

Might be able to use a smaller one (I tend to use components on the "Heavy duty" side of life to avoid overload)

that's good to hear because I ordered this part, I'll just have to figure out which leads to use since it has quite a few more than the exact part.

https://www.ebay.com/itm/123744887539

Checking the compressor leads with a meter was going to be the next thing I do.

Oh, here is a picture of the current relay for reference.
https://i.imgur.com/rFMHBaQ.jpg

Well I got the new relay with no change. The universal replacement had multiple leads so I tried hooking it up according to wiring diagrams with no change so tried swapping them around, no change then either.

So I am fairly confident its not the relay but I'm not sure what else it could be except from what I read the control board or the compressor. Would be surprised if it was either because they were both performing great until the compressor shut off right in the middle of working fine.

Fan works great when I turn it on. When I set the thermostat to just COOL and ON the fan runs then as well but the compressor doesn't start. If I put it on AUTO the fan nor the compressor starts.

I think its significant when on AUTO not even the fan turns on or seems to attempt to run the compressor. It makes me think something that would give those commands is not working properly. I suppose it could be the control board despite it looking pristine, which I had some way to test it and what results I should be looking for.

I really wish there was some temporary bypass I could try to just tell the compressor to turn on regardless of other signals to see if it will even run.

Do you have an energy management system?

mchero wrote:
Do you have an energy management system?

No, as far as I know. Older trailer and has no means to enacting any sort of energy efficiency or scheduling.

Can you see any power at the compressor?

mchero wrote:
Can you see any power at the compressor?

Well when I use this Fluke multi-meter every point I check says "1ac" when set to volts which seems odd. I'm looking for my other multi meter to try that as well.

Tested the meter and it works fine so I am going to say no, power is not getting to the compressor. This is what I thought originally so I replaced the relay but its a different kind of universal replacement as I laid out earlier in the thread.

Diagnosing the compressor is fast. First- check for burnt compressor terminals or burnt O.L. Second- ohm the windings, with cool compressssor, to be sure the internal O.L. is closed.. c-r ohms plus c-s ohms = r-s ohms? If not, kiss the compressor goodbye. Third- There IS a bypass tool called an Annie. Unplug the comp. wires and hook up the Annie, which has manual switches and the capacitors inside, and hit the on and then start button. If it still doesn't start... kiss the compressor goodbye. If it starts, use the volt meter to follow the path to the comp terminals to see whats wrong.
It sound like you know what you're doing. You can do it all with a vom and amp-probe but an Annie makes it fast. I built an Annie in school, mid 70s, for extra points. I bought an Amprobe, vom and a cap. tester as soon as I was out of trade school and they've been indispensable.
Your relay looks like a potential relay and pickup/dropout voltages are critical but who knows what's on these cheap, sh!tty units! Craig

C Schomer wrote:
Diagnosing the compressor is fast. First- check for burnt compressor terminals or burnt O.L. Second- ohm the windings, with cool compressssor, to be sure the internal O.L. is closed.. c-r ohms plus c-s ohms = r-s ohms? If not, kiss the compressor goodbye. Third- There IS a bypass tool called an Annie. Unplug the comp. wires and hook up the Annie, which has manual switches and the capacitors inside, and hit the on and then start button. If it still doesn't start... kiss the compressor goodbye. If it starts, use the volt meter to follow the path to the comp terminals to see whats wrong.
It sound like you know what you're doing. You can do it all with a vom and amp-probe but an Annie makes it fast. I built an Annie in school, mid 70s, for extra points. I bought an Amprobe, vom and a cap. tester as soon as I was out of trade school and they've been indispensable.
Your relay looks like a potential relay and pickup/dropout voltages are critical but who knows what's on these cheap, sh!tty units! Craig

I caught about half of what you said. Everything I learned about capacitors, relays and compressors I learned in the past week working on this AC.

The compressor has a red wire, white wire and black wire connected to it. What do I place where and on what setting to test it for what ever it is i'm looking for?

I checked the leads with wires connected in every combination with the meter on ohms and got a sound on every one.
Should I test the wires this same way while disconnected from the compressor?
The leads on the compressor with wires disconnected?

For further reference my AC looks nearly identical to this one which is what lead me to believe it was the capacitors at first except in my case the fan worked fine.
https://www.youtube.com/watch?v=Ty_ou_TW5EM