Coleman A/C Quit

Scott & Heather · August 24, 2014, 03:27:39 PM

So I have a 3 year old mach III in the rear of our coach. It quit running randomly a couple months ago. No compressor, no fan, nada. Checked all the wiring. Nothing. Swapped out the fan switch (non ducted unit with twist knob controls on ceiling grille). Swapped out the thermostat (swapped using the parts from my brand new mach III unit up front) still nothing. Checked the capacitors, they all checked out good on my analog multimeter. Here's the question:

My front unit (working) has two capacitors in it. My rear unit (dead) has three and the third is black and has a pctr device attached to the top. Can someone sort this out for me? How does my front a/c run without that third start cap? I guess this is what I'm getting at, if my pctr device went bad, can I just use my rear unit without it for now until I get a replacement ordered? I am trying to get the rear a/c up and running and still not 100% sure what's wrong. But it does have power and the fan switch and thermostat are good. All three of the caps tested fine. So not sure where I'm at now other than the pctr and not sure how to run the a/c without it to test.

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luvrbus · August 24, 2014, 03:49:49 PM

Did you add the hard start capacitor Coleman doesn't come with it somebody added it that is probably your problem

Scott & Heather · August 24, 2014, 04:36:09 PM

Hi cliff.

No I didn't add that. It came with the unit. Bought it new from an rv parts outlet in Virginia. So, question, how do I bypass it?

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chessie4905 · August 24, 2014, 05:08:41 PM

You don't need the capacitors to make the fan only run, do you?

luvrbus · August 24, 2014, 05:34:39 PM

Colemans have a fan capacitor,run capacitor and a start relay

Scott & Heather · August 24, 2014, 05:35:10 PM

Where's the relay?

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luvrbus · August 24, 2014, 05:45:52 PM

It should be mounted in that area a small square black gizmo with 5 wires unless they tossed it when someone installed the hard start kit

eagle19952 · August 24, 2014, 07:37:24 PM

i am not a Coleman kinda guy...but... most AC systems have a delay timer that i call an anti slug timer....sometimes they are built into the thermostat.... if it goes bad nothing will work...
THE purpose of the timer is to allow the compressor time to relieve so that it can't start on full pressure.... for instance, if it cycles off and then you immediately change the setting to cooler..it won't restart for two minutes...or to whatever you set it for...
regardless.. if the timer goes,nothing goes....does a coleman have one ?

luvrbus · August 24, 2014, 07:53:56 PM

Coleman has a delay but the fan still runs

eagle19952 · August 24, 2014, 09:01:03 PM

Quote from: luvrbus on August 24, 2014, 07:53:56 PM
Coleman has a delay but the fan still runs

as it will on most AC's.....but not the compressor....ask me how i know..

it can be jumpered....
but you need to become the timer till the new part shows up... some places i have been residential/commercial parts are only sold to licensed vendors.
roof warts...not so much....

Scott & Heather · August 25, 2014, 07:28:18 AM

So I pulled the hard start cap out of the equation. I swapped both caps from the dead a/c to the brand new a/c and vice versa. The new a/c runs perfect on the dead a/c caps. The dead a/c still does nothing. Something is wonky here. Consequently, I forgot to kill the breaker to the front a/c and whilst fiddling with the caps, jolted myself enough to launch my needle nose pliers into the air. Standing on the roof of a 12 foot bus and getting jolted like that is a death wish. Breaker is killed, cap is drained, rubber soled shoes donned, and gloves too. Original boxers in laundry machine. Ok. Taking a breather and then going to chase this one down if it kills me. (Pun intended)

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Scott & Heather · August 25, 2014, 07:59:52 AM

So, finally realized one of my splice solders was bad. Chased it down, and viola. We are in business. Thanks for the help. Sometimes just talking it through out loud is what I need.

happy camper. $0 fix

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Seangie · August 25, 2014, 08:01:26 AM

Scott - I'm assuming you are using a vom and checking voltages? This will quickly tell you what piece is failing. Also, don't be afraid to give airxcel a call. They were very helpful when I called and asked a bunch of questions about the best way to install a thermostat. They also have excellent documents on the website.

-Sean

Scott & Heather · August 25, 2014, 09:03:51 AM

Yeah, I started using the meter to actually trace where the 115v was ending. It ended at a splice. Fixed. In other news, I discharged one of the capacitors into my hand while standing on the wet roof of our coach. Let's just say....my advice? Don't do what I did.

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Seangie · August 25, 2014, 09:07:33 AM

Quote from: Scott Bennett on August 25, 2014, 09:03:51 AM
Yeah, I started using the meter to actually trace where the 115v was ending. It ended at a splice. Fixed. In other news, I discharged one of the capacitors into my hand while standing on the wet roof of our coach. Let's just say....my advice? Don't do what I did.

Scott "Sparky" Bennett