Visit our Popular Forums

Drbles · 05-26-2021, 05:57 PM

Hi everyone, I am looking to purchase and install a Coleman Mach 3 AC unit in place of my Armstrong (1976 24' Argosy). Does anyone have any recommendations, hints, tips, etc? I would appreciate any input! Thanks in advance!

kidjedi · 05-26-2021, 06:40 PM

Does the Armstrong still work? Even if it doesn't, it might be worth repairing. I made the mistake of ripping mine off my first Airstream (I was excited to get started on the work), and now I really wish I'd left it there. My current Argosy (1975) has one, and I love it. If you read up on them, you will see that they are a superb, commercial-grade piece of equipment.

Drbles · 05-26-2021, 06:54 PM

Hi, yes, I was going to fix the Armstrong, but it was in bad shape - needed a lot of parts, and I would have spent over $150.00 just to get to the point where I could turn on the compressor to see if it had a charge. And then if it went out on a trip - we would be stuck.... So I am looking at the Coleman after getting some recommendations. Any tips?

kidjedi · 05-26-2021, 07:18 PM

Quote:

Originally Posted by Drbles

Hi, yes, I was going to fix the Armstrong, but it was in bad shape - needed a lot of parts, and I would have spent over $150.00 just to get to the point where I could turn on the compressor to see if it had a charge. And then if it went out on a trip - we would be stuck.... So I am looking at the Coleman after getting some recommendations. Any tips?

Understood. At the very least, maybe put your Armstrong up on the classifieds once you've pulled it down. They've got a strong following with quite a few people keeping the old ones going.

As far as a new one goes... I'm not much help there. I either keep the Armstrongs going (if they have one), or I tend to find alternative solutions. I've put window units on sliders that come out a hatch on the side or splits with the compressor on the tongue. (I prefer to keep the roof as clutter free as possible for aesthetic reasons).

I'm not sure about the specs on the Coleman, but a heat pump unit along with the a/c seems like a good idea for our trailers. Most people aren't using them in the bitter cold, but a heat pump would be nice for chilly mornings and evenings in the fall and spring.

Best of luck!

Drbles · 05-26-2021, 09:40 PM

I will make the parts of the Armstrong I have available when I can. Thanks for your input.

rowiebowie · 05-26-2021, 09:58 PM

I installed a low-profile Coleman Mach 8 Plus to replace a previous Coleman. Staying with same brand made the install "plug & play" easy using the same wiring harness and thermostat. The foam weather gasket was stuck down so I had to slowing jack the old unit off from the inside. They used some caulk on it from the factory, but I did not on my install. Just cleaned off the old caulk, followed the tightening instructions, and no leaks.

However, switching brands like you'll be doing will complicate things and require at least a Coleman control board. Mine looked like this and is from my 2012 Avenue class b. It worked perfectly with my 2018 replacement ac, but may look different today. If your current ac is not ducted, you may save cost and expense by buying an inside grill with controls and thermostat built in.

https://www.pplmotorhomes.com/parts/...le-new_72.0727

And since you have a trailer, you may have drip cups and tubing for condensation, whereas mine just drips off the back of my motorhome.

On a final note, I hear ac's are in short supply. If you haven't already purchased one, I recommend pplmotorhomes.com in Houston. Good service when I purchased mine and had them ship to me.
https://www.pplmotorhomes.com/parts/...-white_02.2210

SeeMore · 05-26-2021, 10:54 PM

I upgraded a Dometic 13.5K DuoTherm to the Coleman 15K Mach 8 low profile Heat Pump in late 2019. No modifications were necessary to the 14" square opening but I did modify the unit to add a wall thermostat rather than keep the controls mounted on the unit itself. A new digital thermostat capable of controlling both the HVAC unit and the propane heater was mounted at the old wall thermostat location. It was an easy and quite satisfactory conversion. The Mach 8 Plus is built in Kansas and is only about eight inches tall on the roof.

An earlier thread response with part numbers:
https://www.airforums.com/forums/f42...ml#post2403699

I, too, sourced my unit from PPLMotorhomes.

Paul J Mauro · 05-28-2021, 05:49 AM

Quote:

Originally Posted by Drbles

Hi everyone, I am looking to purchase and install a Coleman Mach 3 AC unit in place of my Armstrong (1976 24' Argosy). Does anyone have any recommendations, hints, tips, etc? I would appreciate any input! Thanks in advance!

are they back in stock ?? tried to buy a news one for our rig everyone said last summer they were backordered for months from china manufacturer ?

very funny u tube videos about self installing them
i think I will go to an RV place with a sky crane !

SeeMore · 05-29-2021, 03:52 AM

If you haven't done a similar job before, the piece of equipment that is indispensable is named a "duct lift." Check with a local equipment rental company to find one in your area. It will allow you to do the swap out as a one man task in your driveway. Example:

https://www.ktool.net/sumner-2210-li...00-lb-capacity

**richard5933** · 05-29-2021, 05:35 AM

I changed a roof top unit on our first coach, and it was not that difficult to get the thing on the roof without fancy equipment.

What we did was make a sled from scrap plywood and some 2x4 lumber to ride on a ladder which was leaned against the coach. We used a single piece of a two-piece extension ladder to make a smooth runway. The sled had 2x4 runners on the bottom to keep from sliding off the ladder and plywood sides to keep the a/c unit on the sled.

One rope in my hands pulling up, and another person following the sled up the ladder for extra pushing. Wasn't that difficult to get to the top. Once at the top, the two of us lifted the entire sled & a/c unit onto the roof.

Drbles · 05-29-2021, 08:35 AM

Quote:

Originally Posted by Paul J Mauro

are they back in stock ?? tried to buy a news one for our rig everyone said last summer they were backordered for months from china manufacturer ?

very funny u tube videos about self installing them
i think I will go to an RV place with a sky crane !

I was able to get a Mach 3 right away, but some models are back ordered or bought as soon as they get to the dealer. So they are shipping - and - I think I read somewhere that the one I got was made in America.

Drbles · 05-29-2021, 08:39 AM

Thanks Seemore - we rented a lift from our local rental place for getting our hot tub up on a second story porch - but I think we can slide this thing up on to the bridge I made for doing this (and other) jobs. I have done similar things before ;-)

Drbles · 05-29-2021, 08:44 AM

Thanks RowieBowie - I bought the topside unit and the inside unit together so it will be plug and play - got the digital/bluetooth option which I think will be nice to have ;-)