Replacing AC top unit

[HUGHP]

The squirrel cage came to a literal screaching stop on our 14 year old 15000 Coleman Mach. Isn't wise to just replace the whole unit? Also,is this a DYI for someone with minor mechanical skills? Other than getting the 110 lbs old and new units up and down.

[336muffin]

Replacing the fan motor isn't too bad. I did one of mine in about a hour.

[RTegarini]

Originally Posted by HUGHP

The squirrel cage came to a literal screaching stop on our 14 year old 15000 Coleman Mach. Isn't wise to just replace the whole unit? Also,is this a DYI for someone with minor mechanical skills? Other than getting the 110 lbs old and new units up and down.

I'm curious... is your Coleman Mach A/C unit ducted from the ceiling, using a wall-mounted thermostat, or a unducted unit with no wall-mounted thermostat and the controls on the A/C unit at the ceiling? -RT

[HUGHP]

It is a 15000 Coleman Mach A/C unit ducted from the ceiling, using a wall-mounted thermostat

[youracman]

I put a new Mach 15 on my Class C a few weeks back, Hugh. Not a big deal, but a few notes: 1. You will need to keep your old control board; my new unit came without one. 2. On my rig all the stat wires were the same color ... so I marked them with tape before unplugging from the control board 3. The freeze sensor/switch also plugs into the control board and you will need to keep your old one. No polarity to the 2 wires just note where they plug in. Also note the approximate location where the freeze sensor itself was "pluged in" to the evaporator fins. (Phone pics are always a good idea.)

By FAR the "trickiest" part of the job is getting the old unit off the roof and the new one on. You'll need to pick up the new unit and set it back down each time you adjust the position over the opening (to get it fairly centered) cuz there is a thick foam-like seal on the bottom side of the unit that you don't want to damage. In my case I had a strong nephew and his strong friend to do the heavy lifting ............. I did the inside stuff.

BTW- I was surprised how much colder air the new one puts out. I believe the 10-yr-old unit had weak valves.

Mine is a ducted unit with a wall stat. A non-ducted unit might be even simpler to install.......dunno.

I'd say go for it. Took about 3 hours. Best of luck.............

[Jim_HiTek]

I'd consider this...when you repair your A/C, it will be no better, but NO WORSE then it was before you repaired it and it was working. So if you were satisfied with it's performance before it failed, save the money. If you weren't satisfied, get a newer unit.

[Duner]

My 14 yr old coach has the Coleman basement unit and it came with metal squirrel cage which broke after about 4 yrs. I replaced it with the newer design made of composite plastic. I suspect your roof unit has a similar redesign. It will run much quieter too.....for 10 yrs now.

Check the brass bearing on the outdoor blower shaft. It may be worn and quite loose. I replaced mine with a sealed ball bearing version from Graingers that is only a few dollars more and has the same dimensions.
Link here.

Good luck,
Bill

[wmckinley]

Last time I swapped out my roof ac I learned to take a good ladder, the longer the better, lean it against the roof, dismount the old unit and slide it down the ladder Leave the new one in the box and slide it up.

[idoxlr8]

Just replaced the fan motor in our old coleman unit last week. About $157 for the motor, works great now.

[RTegarini]

Originally Posted by HUGHP

It is a 15000 Coleman Mach A/C unit ducted from the ceiling, using a wall-mounted thermostat

Thanks for the reply. If the motorhome is nearby, could you tell me the thermostat make and model number, along with the specific A/C model number? Mine uses two Coleman Mach thermostats that are slightly different from each other with two different part numbers and I'm having a heck of a time finding the correct A/C unit to replace my rear air conditioner to go with my OEM thermostats.

Thank you. -RT

[CoveredWagon]

I recently replaced my 2005 Coleman Mach 13.5 with a factory reconditioned Coleman Mach 15 unit. My old one had compressor issues and kept tripping breakers. By buying the reconditioned unit I saved about $200! Installation was much easier than I expected too! I leaned a sheet of plywood against the side of my RV to use as a slide. After removing the 4 bolts that hold the old unit to the roof and disconnecting the wires, I used some nylon ratchet straps (Harbor Freight Specials) to lower the old unit to the ground. I was still recovering from having 2 cervical discs repaired so I called a 35 year old neighbor to help! With 2 people handling the weight it wasn't too bad. We then lifted the new A/C (still crated) using the same method and uncrated it on the roof. I cleaned the roof area around the ceiling duct, set the new unit in place, bolted it down and re-attached the wiring! Simple!

[Hicks3456]

I have a 2016 Winn Vista LX with front and rear air conditioners. Lately when the rear unit starts there is a squealing noise that disappears after it gets running.

I assume it is a bearing going bad. Is this something that can be replaced easy or is the whole unit considered disposable?

[corjaguar]

Most mobile rv mechanics charge between 200 and 300 dollars to r/r a roof air....ducted or unducted.

[creativepart]

Originally Posted by Hicks3456

I have a 2016 Winn Vista LX with front and rear air conditioners. Lately when the rear unit starts there is a squealing noise that disappears after it gets running.

I assume it is a bearing going bad. Is this something that can be replaced easy or is the whole unit considered disposable?

The answer to your question is yes.

Yes, the fans (there are two) and the fan motors are replaceable. Bearings? I believe are built into the motors. I'd guess that an electric motor shop could tackle the bearings if you removed the motors and brought them to their shop.

And Yes, these A/C units are treated as disposable. The main reason seems to be the pain in the butt location of a unit this big and heavy 11' off of the ground. To repair them or even see if it can be repaired requires taking it off of the roof and bringing it into a shop and leaving it for a few days to a week.

The A/C seems to only really break down in the heat of the Summer and most of us want to get our RVs cool again ASAP and that requires buying a replacement and getting it up there. So, that's what we do.

My rear A/C went out 40-days after the 2-yr warranty while on a trip with a tight travel schedule in Missouri when the temps were 100 degrees. Could it have been fixed? Maybe. But it could be replaced in about a day and we could be on our way.

[creativepart]

A major fail point is the A/C squirrel cage fan.

https://www.youtube.com/watch?v=SAAFKcxi3jg