Capacitor issue, Coleman Mach Basement unit.

[Vibrant93]

My '00 Itasca has a basement A/C (non heat pump) unit and I'm having issues with the 2nd compressor. Just wondering if my symptoms are common for a bad start/run capacitor...? I'm dreading a bad compressor! My coach is a 30amp unit. While on shore power (true 30amp service) and with the thermostat set to call for a/c, the 1st compressor starts and runs as normal. About 30 seconds after the 1st compressor starts the system tries to start the 2nd compressor and fails to do so. I get an amperage spike to about 30 on the gauge and then it starts to automatically shed power to specific components. The 2nd compressor being one of them. On generator power I'm getting basically the same results except instead of shedding power to systems, it'll just trip the 120v accessory breaker on the actual generator its self. I guess my question would be, what are common symptoms of a bad start and or run capacitor? Would a system still try to start but pull a huge amperage load like I'm seeing? I was inside the panel last night hoping to see a bulged capacitor but they both looked good visually. Capacitors are pretty cheap so I'll probably just put them in but figured I'd ask here too.

Thank you.

[2manytoyz]

A bad run capacitor can cause the compressor to continue to try to start without the benefit of phase shifting. It lacks the necessary torque without it to spin the motor.

I've had to replace a few run capacitors on my previous RVs, and about every 2 years on my 5 ton A/C unit on our house.

This is a common problem, and will likely be a cheap fix. I've learned that local A/C shops don't want to sell to the public, so I buy my parts on Amazon for a fraction of the price, and get it in 2 days. So much for helping local business.

Make sure to disconnect all power sources before digging into the box. I've never worked on a basement model. Here's what a roof top Coleman looks like to remove the access panel. Yours might be similar.

[dmck413]

You could replace your start capacitor with a super boost to try.It sounds like a locked up compressor.