Air conditioner problems

bedbug123 · 07-08-2021, 11:27 PM

A/C will not run on generator or shore power?

When home I plug into standard wall outlet, 110.

Just does not come on at all, is a Coleman Mach 8

Breaker on convertor is on, I switched off then back on, still no start.

At thermostat the heater will start, but not AC.

Any trouble shooting help out there, thanks

Judge · 07-09-2021, 12:13 AM

You need to provide more information. Coach make, model, year, 30A or 50A etc.

The converter has nothing to do with the A/C unit. The A/C unit should have it's own breaker in the power distribution panel. You want to reset it and see what happens.

If you switch it to Fan Only, will the fan turn on? If not, then it is either an AC power issue to the unit or it could be a thermostat / thermostate wiring issue.

If you can get the fan to turn on but not the A/C, then it could be the capacitor in the unit.

bedbug123 · 07-09-2021, 01:50 AM

2006 hurricane 30 AMP, FORD CHASSIS

MJC62 · 07-09-2021, 01:59 AM

Judge gave you good advise. I will reiterate does the fan run? If the fan runs, then there is a good chance it's a bad start capacitor. Had to replace mine on an 06 Gulfstream

bedbug123 · 07-09-2021, 01:23 PM

fan does not run nothing runs, have switched breaker off then back on no change.

will start looking for 110 and 12V power issues

javelin · 07-09-2021, 03:47 PM

I don’t know your coach specifics. You checked the 120VAC breakers and I assume all other AC systems are working on shore and generator except for the A/C system? Since the call for heat from the thermostat is working OK you say, but no A/C fans or compressor action, possibly there is a common problem in the thermostat wiring or plenum control relays specifically related to the A/C unit. The thermostat must be getting +12vdc for the call for heat to work. Check to see if there is a connection strap between RH and RC terminals (if your thermo has them). It may only have one terminal marked R which would connect to the +12vdc supply......usually through a fuse. This should supply +12vdc to the A/C portion of the thermostat.
Usually the thermostat terminals are labelled B for ground; Y for A/C compressor control relay; and GL and GH for the A/C fan low and high speed relays. Typically these 120vac control relays are up in the ceiling A/C plenum (probably in a metal junction box). When you call for A/C fans or cooling the appropriate mini relay in the thermostat should close (you should hear it if you listen very carefully) and supply +12vdc to operate the appropriate 120vac ceiling control relay and that relay would then connect the 120vac through to the fan or compressor in the roof top A/C unit. Since neither compressor or fans work then maybe the common ground B terminal has a problem connection or the +12vdc RC (if provided as a separate terminal) is not providing +12vdc for the cooling portion of the thermostat.
You might also have a 120VAC connection problem somewhere at A/C breaker and ceiling plenum control relays. Attaching an old connection diagram that may help. Note that your coach may be wired differently though and take care on live 120VAC circuits if you access them.

**16ACE27** · 07-09-2021, 04:39 PM

Javelin's dig into the thermostat is good info IF this is a pre-owned RV and the A/C never worked. If the A/C has worked and now all of a sudden doesn't; it probably is not a thermostat problem especially since the furnace still works, so you know it is getting 12 VDC control power.

I'd pull the outside cover and open the electrical access and verify with a voltmeter that 120 VAC is making it to this area. Then either troubleshoot the A/C control relay, etc (if 120 VAC available) or troubleshoot why 120 VAC is not making it to the A/C (if no 120 VAC available).

The thermostat wiring could still be the problem (or the thermostat itself) if something there has just broke, but it's more likely a problem in the A/C itself.

bedbug123 · 07-12-2021, 03:00 PM

I started trouble shooting issue today , and now the heater wont come on. Although it is hot out, shouldn't it start fan if set to 90 and inside coach is 80 degrees?

So at this point the thermostat doesn't run ac, fan or heater functions.

I assume if switch on t stat panel is set to fan on...... the fan that blows the cold air around to the inside ac roof ducts should run?

**16ACE27** · 07-12-2021, 03:57 PM

Quote:

Originally Posted by bedbug123

I started trouble shooting issue today , and now the heater wont come on. Although it is hot out, shouldn't it start fan if set to 90 and inside coach is 80 degrees?

So at this point the thermostat doesn't run ac, fan or heater functions.

I assume if switch on t stat panel is set to fan on...... the fan that blows the cold air around to the inside ac roof ducts should run?

Yes, the furnace should come on if the thermostat calls for heat and the A/C fan should always run if set to ON.

So now I'd break out that multimeter and verify 12 VDC control power to the thermostat. If you don't have it, back trace to the furnace (the source of 12 VDC to the thermostat) and then the fuse panel.
If you do have the required 12 VDC control power to the thermostat then maybe it has gone bad. What type of thermostat do you have?

bedbug123 · 07-13-2021, 01:45 AM

Thermostat is Coleman Mach, made by RV products. It is a electronic, has a pc board.

Today I was testing thermostat, to control box on AC, (got trouble shooting guide from RV products) I as getting 12V to that AC from T stat? wouldn't that mean it is working and getting power from heater?

Just seems strange the heater came on twice when I tried, but then it does not come on anymore, all fuses in power box ok

Chateau_Nomad · 07-13-2021, 04:56 AM

Can you hear a hum or buzz coming from the AC? Pop the thermostat off the wall, get a schematic and check for loose wires... AND voltage as suggested. Intermittent problems scream loose wires.

P.S. I replaced the crappy stock thermostat with a basic Honeywell digital thermostat designed for residential use... works fantastic - and accurate temp control.

bedbug123 · 07-13-2021, 03:14 PM

I hear nothing from AC when trying to turn on. It is way to hot to go on roof to work so I and trouble shooting from inside. I like your idea a Honeywell t stat, I guess as long as it has the same wire count and colors.
They also run 12V

do you remember what model you bought? are you using it in an 5th wheel, pull along our drivable unit?

**16ACE27** · 07-13-2021, 03:30 PM

Quote:

Originally Posted by bedbug123

I hear nothing from AC when trying to turn on. It is way to hot to go on roof to work so I and trouble shooting from inside. I like your idea a Honeywell t stat, I guess as long as it has the same wire count and colors.
They also run 12V

do you remember what model you bought? are you using it in an 5th wheel, pull along our drivable unit?

This is the Honeywell thermostat I put in our ACE to replace the analog Coleman Mach thermostat:

https://www.amazon.com/gp/product/B000GGPMO2/

It is not a wire-by-wire replacement but there are numerous tutorials on Utube University showing how to install. This is one of many:

https://www.youtube.com/watch?v=Kc9ybuOslSo

bedbug123 · 07-15-2021, 05:51 PM

I got back on AC issues, today I checked 110 voltage, had no to AC. Breaker seems ok, but I ordered one to replace it. Should be here by Saturday.

But as always I think of grounding issue, but how would I check this out?

**16ACE27** · 07-15-2021, 06:55 PM

Quote:

Originally Posted by bedbug123

I got back on AC issues, today I checked 110 voltage, had no to AC. Breaker seems ok, but I ordered one to replace it. Should be here by Saturday.

But as always I think of grounding issue, but how would I check this out?

To make things clearer:

A/C = Air Conditioning
AC = Electricity (as in 120 VAC or 240 VAC)

bedbug123 · 07-15-2021, 11:06 PM

both AC meant air conditioner in this post, next I time I will use A/C

Wiley1 · 07-17-2021, 07:06 PM

Quote:

Originally Posted by bedbug123

I like your idea a Honeywell t stat, I guess as long as it has the same wire count and colors.
They also run 12V

There have been many discussions in these forums about installing a residential thermostat in an RV. Generally an RV thermostat runs on 12vdc and a residential model runs on 24v. If there is such a thing as a thermostat that will run on either voltage, I wasn't able to find it when I did my conversion. I ended up with a Coleman 12v digital with Bluetooth just because I didn't want the complexity of trying to convert from one voltage to another.

Whichever thermostat you choose, please make triple sure that it will run on 12vdc.

**16ACE27** · 07-17-2021, 09:18 PM

Quote:

Originally Posted by Wiley1

There have been many discussions in these forums about installing a residential thermostat in an RV. Generally an RV thermostat runs on 12vdc and a residential model runs on 24v. If there is such a thing as a thermostat that will run on either voltage, I wasn't able to find it when I did my conversion. I ended up with a Coleman 12v digital with Bluetooth just because I didn't want the complexity of trying to convert from one voltage to another.

Whichever thermostat you choose, please make triple sure that it will run on 12vdc.

No voltage conversion required. The referenced Honeywell thermostat uses battery power for control and easily switches the 12 VDC power used to control the furnace and A/C.

MEWright · 07-17-2021, 10:46 PM

Quote:

Originally Posted by bedbug123

A/C will not run on generator or shore power?

When home I plug into standard wall outlet, 110.

Just does not come on at all, is a Coleman Mach 8

Breaker on convertor is on, I switched off then back on, still no start.

At thermostat the heater will start, but not AC.

Any trouble shooting help out there, thanks

I just replaced 1 of my Coleman A/C units on my roof. It is super easy. I wrote a full blog about it on IRV2 with good detailed pics. SUPER EASY took about 1.5 hours. I spent a few weeks and threw some parts at the old one, new start capacitor, fan capacitor etc, fan would run but due to low pressure it would not start the compressor..... Unless you are an AC tech and have the ability to weld in ports to check Freon levels, nitrogen to pressure test the system to find the leak, torch's to weld the leak and Freon on hand to recharge, they are not worth fixing. BTW, I am and it still was not worth fixing. Cost 803.00 for a new one.

MEWright · 07-17-2021, 10:47 PM

Quote:

Originally Posted by MEWright

I just replaced 1 of my Coleman A/C units on my roof. It is super easy. I wrote a full blog about it on IRV2 with good detailed pics. SUPER EASY took about 1.5 hours. I spent a few weeks and threw some parts at the old one, new start capacitor, fan capacitor etc, fan would run but due to low pressure it would not start the compressor..... Unless you are an AC tech and have the ability to weld in ports to check Freon levels, nitrogen to pressure test the system to find the leak, torch's to weld the leak and Freon on hand to recharge, they are not worth fixing. BTW, I am and it still was not worth fixing. Cost 803.00 for a new one.

But I kept the old capacitors, fan motor and squirrel cage for parts.. JIC

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