A/C shutting off

[viktor]

Friends: My A/C unit in my 2004 Vectra is now shutting off and only the fan operates after a minute of operation. The thermostat is the Coleman-Mach True Air 6535-3451. The other controls work, but when setting the control to Cool the A/C comes on for a short period blowing cool air and then the compressor quits and only the fan operates drawing in outside warm air.

[MrMark52]

Very common with these units - disconnect power from your coach, or flip the breaker off.

Grab a 1/4” and 5/16” nut drivers, and a #10 flat blade and Phillips screwdrivers and climb up on the roof.
Take a water hose with a gun sprayer with you as well.

Climb up on the roof and go to the unit. Take the big shroud off the unit to expose the working parts.
Find the box with wires going into it from the compressor and fan motor and open it up. Inspect all the wiring for burned wire terminations and/or signs of overheated wiring. Repair as needed.
If you don’t find any wiring issues - then take a picture of any markings on the metal run capacitor and the PTC start device.

Identify which direction air flows thru the condenser coil, and use your water hose to spray water in parallel with the cooling fins in the opposite direction as the air normally flows thru. It’s OK for wet overspray to get on the fan motor or compressor, just don’t saturate or flood them with water.
Be careful not to flood water back toward the enclosed evaporator section or you’ll have water all over the floor inside (not a bad idea to put down some painters plastic before starting to wash).

If you found electrical issues and repaired them, reassemble the unit, crawl back off the roof, power the circuit or coach back up, and test.

If you didn’t find any electrical issues, replace the silver metal bodied run capacitor (either based on the pictures you took, or by locating the service and parts manual for the unit). I doubt the PTC hard start has failed, but for what it costs, replace it as well.

Once done, test.

It is possible your compressor could be on the wain - it happens, not a lot you can do to extend its life.

[viktor]

My unit is a central air conditioner/heating unit located in the rear near the engine; not on the roof. Has anyone tried to repair this unit. A local shop that does not have the equipment to replace it advised me that it had to be replaced; not fixed. I am not sure if this is correct.

[l1v3fr33ord1]

Viktor-

The "basement" air conditioner is an oft-discussed topic on this forum. Here is a current thread, started by an iRV2 user ("Jim HiTek") with experience troubleshooting and repairing these units:

Basement AC gone

The positive news is that many of the components can be replaced or repaired. The negative news is that many RV mobile repair people don't want to touch the basement units.

Some failures can be diagnosed and repaired without removing the entire unit. Some failures require dropping the unit down-and-out to reach components. I understand from reading (never having owned one myself) that these units are "residential" air conditioners, and once you get them out of the coach many residential (not RV) technicians can diagnose and repair them. And, there's enough written material so that a do-it-yourselfer can make many repairs.

I'd read the thread listed above, then send "Jim HiTek" a private message asking for guidance.

[viktor]

Thanks for the response. I hope the repair will be easier than trying to print out the removal instructions. Google has apparently denied permission.

[l1v3fr33ord1]

Viktor-

If you send me a private message containing your e-mail address, I'll send Duner's instructions to you that way. They are too large to upload here.

You can get to "Jim HiTek's" instruction by the link in his post on the other thread, here.

[DancinCampers]

Does the unit work in the electric heat mode?

[viktor]

The unit works in all the other modes. Thanks for the response.

[DancinCampers]

If the unit works well in the electric heat mode then this would indicate the compressors, etc work. In the electric heat mode all the compressors, etc are controlled by the pc board in the unit, once it receives a signal from the tstat.
In the cooling mode all compressors, etc are controlled by the tstat. It appears you are losing the control circuit on wire Y1 which controls the #1 compressor. If your freeze sensor was bad I expect it would not start at all.

I would start by removing your tstat cover and spray some contact cleaner into the slide switch area for selecting the cool mode. You could also remove the tstat from the wall and if you have enough slack you could check the connectors. The smaller connector should be for the gas furnace.
I believe the center wire on the 9-pin connector, yellow color, is the control signal for #1 compressor. You could check with a dc volt meter to see if you have voltage when the compressor shuts off.
You should be able to find the tstat wiring info online at Airxcel, to make sure my info is correct.

[viktor]

Friends: Apparently I mispoke. I now realize that the electric heat does not work. I thought that when it shut off it had reached the set temp. However, it was also shutting off after a few minutes. I did try your tip, but it did not work. I thank you for the tip, however.

[Ray,IN]

Originally Posted by l1v3fr33ord1

Viktor-

If you send me a private message containing your e-mail address, I'll send Duner's instructions to you that way. They are too large to upload here.

You can get to "Jim HiTek's" instruction by the link in his post on the other thread, here.

Here is the 6535 service manual: https://bryantrv.com/docs2/docs/rvp/6535heatpump.pdf

Duners instruction info is in the files section of irv2.com
Otherwise it's here too:https://www.winnieowners.com/forums/...ure-42567.html
Jim Hytek followed Duners instructions, but did a lot of unnecessary work, like removing the MH rear cap and ductwork. Jim did get more detailed in some areas, which is a good thing.
Duners instructions are the best IMO, even though it doesn't cover the details of removal completely for all brands of MH's.

[viktor]

Thanks for the information. Greatly appreciated.

[Qui-Gon John]

If the unit is original to the RV, probably time for a new one. We just replaced the one in our 2006 Winnebago Aspect. Got a Coleman-Mach, Mach 8 w/Heat Pump. Additional benefit is with fan on Low, it is much quieter than our old unit.

[Vectra 2020]

Originally Posted by viktor

Friends: My A/C unit in my 2004 Vectra is now shutting off and only the fan operates after a minute of operation. The thermostat is the Coleman-Mach True Air 6535-3451. The other controls work, but when setting the control to Cool the A/C comes on for a short period blowing cool air and then the compressor quits and only the fan operates drawing in outside warm air.

One thing you might try before you take everything apart is check the thermostat. The Coleman mach type are prone to failure, I also have a 2004 Vectra, and had issues with the thermostat last winter, I found a site that sold an upgraded T-stat specifically for my rig ( https://www.microair.net/collections...n-replacements)
It was basically a plug in replacement, and now I can also program it via Bluetooth or wifi, has been trouble free since then.
Just my two cents,
Cheers!