Community Forums

dave&ginny · 06-28-2018, 11:03 PM

I’m still having problems with my number 2 air conditioner. I checked the balesters and they aren’t burnt as some have suggested. Today I called the Coleman service center and he suggested putting a jumper across the “freeze” line. No joy

No oil residues at all and the unit looks clean. The compressor cycles every 40 seconds for about 2 seconds. When it does I can feel coolness on the coils. Unfortunately I’m not much of an a/c mechanic. And the Coleman service center seemed a bit annoid since I’m not a technician. Any ideas what to check next?

Rollin101 · 06-29-2018, 05:41 AM

Sure sounds like the start capacitor. Sometimes you can tell if they're bad by looking at them, sometimes not. I would replace it.

brobox · 06-29-2018, 05:54 AM

Dave, it sounds like it is a bad run capacitor? They are easy to change less and than $10. at a supply house If you do get one go to an A/C supply house in town, not an RV parts store, which would probably have to order it anyhow. Also an A/C supply house can give you excellent trouble shooting advice. These are pretty simple units. If you replace one, I would replace both the start and the run capacitors at the same time, they are located next to each other. IIRC, the capacitors are inside of a black box on the Mach 8.

dave&ginny · 06-29-2018, 10:36 AM

Thanks guys I’ll try that as well. I just got off the phone again with the service people and they suggested to pull the white wire off the high pressure limit switch. I’ll try that tonight when I get home and if that doesn’t work I’ll get the capacitors

gswindle · 06-29-2018, 10:56 AM

I pulled the white wire going to the pressure switch on my unit and it has worked great every since. It was only blowing air. it started working immediately. You need to make sure you turn off the breaker before you do it.

Gary

mymyst · 06-30-2018, 06:25 AM

if you have and know how to use a multimeter, it is easy to test the capacitors. Once power is turned off, remove the leads from the subject capacitor. Discharge the capacitor by applying a screw driver acorss the capacitor terminals. Set your multimeter for checking conitnuity. Apple meter leads across the capacitor terminals. If the capacitor is good, you should see a positive needle (or immediate positive continuity indication, if meter is digital) movement on the meter, followed by an immediate drop to zero. If needle doesn't move, or goes positive and stays there, the capacitor is bad. If bad, they are cheap at an ac supply house.
Sounds like a bad run capacitor from your description. Also, if a defective high pressure switch is found to be the culprit such as in prevpost, it should really be replaced with new, or if it is tripping aaaaand not defective, look for the cause, ie; dirty condenser coil, or possibly smashed condenser fins. Good luck!!

dave&ginny · 06-30-2018, 06:48 PM

I crawled up on the roof last night in 96 degree temps and pulled the white wire off and it didn't help. Today I called Camping World in Davenport Iowa and they had 2 start capacitors in stock so off we went for a 1.5 hour drive and picked them up. I figured if one a/c unit went down because of the capacitor the others might as well, and I like to carry spare parts.

So in the blistering heat, up the ladder I went. I believe I broke a sweat as I left the inside of the RV. I changed out the capacitor and .....No luck.

I think I've tried about everything a shade tree mechanic can do. After our trip to the A.I.M. rally, I'll get it into the shop. I really don't need the 2nd a/c unit because our coach maintains 68 degrees with just 2 but if one of those go out on this trip I might be a bit upset.

I was told a new unit will cost about $950 and I might just buy a new one and save this one for parts.

LWBAZ · 06-30-2018, 07:20 PM

Quote:

Originally Posted by brobox

Dave, it sounds like it is a bad run capacitor? They are easy to change less and than $10. at a supply house If you do get one go to an A/C supply house in town, not an RV parts store, which would probably have to order it anyhow. Also an A/C supply house can give you excellent trouble shooting advice. These are pretty simple units. If you replace one, I would replace both the start and the run capacitors at the same time, they are located next to each other. IIRC, the capacitors are inside of a black box on the Mach 8.

Dave, my reading of Chuck's post quoted above suggests there are two capacitors per AC unit.

Did you replace both of them or just one?

brobox · 07-01-2018, 06:31 AM

Dave, there is also a difference in the start and run capacitors. You mentioned yours started, but quit in a few seconds.....run capacitor suspicion.

mymyst is correct about testing the capacitors for continuity. Lot's of photo post on the internet of how to's. Let us know what you find.
Check for an AC supply house closer than CW and explain what you have done, the counter guys at those places are sharp, they deal with those problems everyday, most use to be AC techs. The guys at CW were selling tents yesterday.

It was explained to me once that an RV A/C is nothing more than a window A/C unit made to mount on the roof.

dave&ginny · 07-01-2018, 06:42 AM

Quote:

Originally Posted by LWBAZ

Dave, my reading of Chuck's post quoted above suggests there are two capacitors per AC unit.

Did you replace both of them or just one?

You’re right there are 2 capacitors. One is for the fan which is working great and the other is for the compressor.

dave&ginny · 07-01-2018, 06:44 AM

Quote:

Originally Posted by brobox

Dave, there is also a difference in the start and run capacitors. You mentioned yours started, but quit in a few seconds.....run capacitor suspicion.

mymyst is correct about testing the capacitors for continuity. Lot's of photo post on the internet of how to's. Let us know what you find.
Check for an AC supply house closer than CW and explain what you have done, the counter guys at those places are sharp, they deal with those problems everyday, most use to be AC techs. The guys at CW were selling tents yesterday.

It was explained to me once that an RV A/C is nothing more than a window A/C unit made to mount on the roof.

I gree about CW! I’ll call one of those shops and see what they say. The schematic shows both capacitors, with one for the fan and the other for the compressor. Since the fans start right up I don’t see how the second capacitor can be the problem.

When I spoke with one of the techs he said either a stuck compressor, circuit board issue or a bad thermostat

brobox · 07-01-2018, 07:06 AM

Quote:

Originally Posted by dave&ginny

When I spoke with one of the techs he said either a stuck compressor, circuit board issue or a bad thermostat

When one of my AC's went out in SD, closest one was in Denver, I found how to test all of those units on the internet. When I got up on the roof to run the test, found the front of the unit was soaked with Freon. Had to go to Denver for the new unit