Coleman Mach 8 A/C - control box replacement

[@randallrich7051]

Great video, as i have to replace mine. The fan relay is stuck on.

[@tbftrev]

It was easier than I though, just make sure to know where each wire goes when taking off and putting back on. I marked mine 1-7 with a paint pen.

[@gurcsik]

Hey there, my Coleman Mach unit is just not powering on at all, nothing on the display. I am away on a work trip troubleshooting this with my wife who is with the RV. I am assuming the control box could be the culprit if nothing is turning on with the unit, but wanted to see what you thought. Curious if it could be something else. The RV is getting shore power and runs on a generator just fine. My wife was running the AC today and it suddenly turned off, and our Bulldog surge protector tripped red.

[@tbftrev]

I realize you are not there, which makes things more difficult. The first things to try obviously are the circuit breakers. The reason I say that is because your watchdog tripped, which could have popped a circuit breaker (it may not have since it sounds like the watchdog took the hit). Is the watchdog still red? Running on Generator, know that you have to let the Generator run for about 5 minutes to fully power before your A/C will kick on. I typically leave the A/C off, run the generator for about 5 minutes then turn the A/C on. If Circuit breakers are fine and Generator is powered up, and still no A/C there are still some other steps to test. I am not sure of your wife's abilities here but the following may be some steps to take. 1. (POWER OFF) On the ROOF, take the cover off the unit and then there is another cover over the control box. In 1:55 (in the video) then just visually look at it. at 3:09 (in the video) you can see I immediately saw that there was a burnt connection. So first thing to do is visually inspect the system. 2. Check input power, is the system getting power to begin with, You need to check this at the unit, and it typically will be the large RED and BLACK wires coming into the relays. (Sorry I'm not super specific, I am not sure on each unit but on mine it is the RED and BLACK that comes into the Compressor Relay in the control board.) 3. The next are things I have not really done, but you may have burned out a capacitor, (this can be dangerous to check because capacitors retain charges and can retain them even after disconnected) look up how to discharge a capacitor prior to testing it or messing around with it. I am not an Expert on A/C's but hopefully this helps get you started, if not, PLEASE CALL A MOBILE Local RV tech, they will typically be cheaper than a dealer.

[@terrychavis3080]

What were your signs and symptoms?. The reason i asked, my A/C will cool great when first turned on however when it reaches its desired temp and shits off, it wont cool again on restart. Let it sit a while and it will cool again.

[@tbftrev]

We were not getting cool at all. The one thing I did was just open it up and take a look at it and found the problem. Yours sounds like a switching or thermostat switch sensor. But not sure