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Captain8 · 06-01-2023, 05:00 PM

Of my 6 AC units
#1 works perfectly fine
#2 worked fine for a while but just stopped getting cold
#3 dead
#4 sometimes shows up on thermostat and when it does a few times the compressor has locked up
#5 worked once but now dead
#6 dead

Whats the best option to bench test these units? I know some are dead but others might just be programmed not to have power. Are all the control boards interchangable or anything to worry about there?

The plan is to setup #1 and #6 with my Furrion 15.5k ones from my old coach, then #2 and #5 with Dometic Brisk 2's I have new in box laying around.... so only need 2 of them in perfect working order.

Why do I have 6 AC units in a 40ft rig? no clue but might as well have them available.

MrMark52 · 06-01-2023, 05:33 PM

If all the units are the same age - I would disconnect power from your coach, then climbing up on the roof and taking the top covers off of them. Open up the electrical box and look for burned wiring and conditions. This is a very common issue with MoHo/RV A/C units.

Also inspect the capacitors and hard start components for swelling and/or issues such as their falling apart.

While your up there, clean the condenser coils.

Close up the electric box.

Climb back down and open up your breaker panel - and then remove the front plate covering the breakers. Inspect all internal wiring inside the panel for burned wire/connections or loose connections. Repair as needed.
Tighten all wire clamping screws.

Plug the coach back in.

One at a time, turn each unit on and climb back on the roof to determine its operating characteristics - compressor running, fan motor running.
Fan motors may need lubrication - and while they may not have oil ports, they can be relubricated, but require removal from the unit.
If the compressor isn’t running, it’s possible the run capacitor is bad, the start components are bad, or there could be an issue with the wiring at the compressor. Note if the compressor is warm or hot to the touch. Do not access the wiring on the compressor before removing power from the coach once again.

Your fortunate you have 6 units to work with to swap parts around (capacitors and hard start components) which could be the issue with the units that don’t run.

If you see signs of oil on any of the refrigerant tubing, chances are you might have lost part or all refrigerant in that unit.

Finally, when you have power disconnected from the coach, or once you’ve confirmed the breaker panel is OK you can switch the AC breakers off. Once you know power is off to a unit, access where the 120VAC power wiring enters the unit and confirm all three connections (hot, neutral, and ground) are good (none overheated or burned).

All of the above sounds like a mountain of work - and it will be, especially if it’s hot up on the roof and depending on your electrical troubleshooting skills.

95% of AC unit issues are electrical so an understanding of how motors and capacitors work together is important in troubleshooting.

RS505 · 06-01-2023, 05:53 PM

I have two penguin rooftop units that I’m about to pitch in the trash. One works, the other was working until an overheated power wire shorted out the board. I have the thermostats too, and an aqua hot controller.

I have limited time and patience to fix stuff, so I just replaced everything. You can pick them up in Albuquerque.

Captain8 · 06-01-2023, 08:18 PM

Thanks for the info. I took a quick look and seems for #2 a wire came unplugged from the easystart I just installed. It was a rush job so didn't spend much time securing it all. Also seemed when I was up there #4 started working so might have just been bad comm cable since I have thermostat set to 1,2,4 as 3 needed bypassed or nothing worked.

I finally unboxed my brisk 2 evolutions and one is 15.5k and other 13.5k and neither of them have controllers just the roof units so there's just a 6 pin plug.... gotta figure how that works and what I need.

Now I gotta kinda rethink where I'm putting the ACs. The Furrions have easystarts builtin and I have 1 easystart I just bought setup for #2. In my coach #5,#6 are in the bedroom. #4 is for the bathroom and fridge area then 1-3 are the main living space. I only plan on running 2 ac units 95% of the time. I'll then run 4 acs only to cool the coach off battery power then if it's really hot and been sitting a while I'll fire the genny and run all 6 for a few. The furrions are very efficient, quiet and powerful but they each have their own thermostats currently. I have a microair quad thermostat that worked for my penguins but I figured these are the least efficient since they're 10 years old. Then the brisk2s I need to get controllers for.

#1 and #5 make the most sense to be the main ones. #5 or #6 needs to be the quietest since it'll be on above when we sleep. #3 is the most central so if I just ran 1 this is the one. 2,4 are most pointless

Off to Google and hopefully I can wire the brisks with the penguins. It all seems like they should have manual thermostat wires so might be time for me to build a smart controller or find something to connect to ervin system I'm planning on building.