Replacing RV Air Conditioner units

[ScottandLori]

We have owned a 2005, 36 foot Mobile Suite (RS3) for about 2 years now. The front air conditioner in the bedroom area (Zone 2) appears to be original but will only run for a short time before making a new different noise then causing the breaker to blow. The rear air conditioner in the main living area (Zone 1) is running but the two air conditioners do not communicate well. I have already replaced the thermostat. We have watched several youtube videos showing how to remove the old AC units and install new ones, but all of them remove the anchoring bolts from the inside, in an access hole through the ceiling. We have a ducted system and we can not see inside how to reach the units from the inside. How are these units mounted or how do we get to them? There are no visible access ports to the units from the inside.

[wingnut60]

Welcome to the forum.
The bolts are accessed from the top, there are 4 of them. While I haven't done this replacement myself, have read of several who have and they say the hardest part is getting the old unit off to the ground and the new one up on the roof.
Need to be careful of the replacement units due to the age of your trailer--need to verify with Dometic about the compatibility of the wiring and of the thermostats. Several of the posts mentioning replacing old units said they had communication problems with the thermostats.
Will need new lower gasket kit for sure. Take the A/C cover off and look around for the lag bolts that are screwed into the roof--probably hidden and/or covered by caulking.
I had a 36TK3 for 10 years and luckily never had to replace an A/C.
Good luck.

[Walt]

Circuit boards are different from old AC unit to new ones. You also have to replace thermostat to the new style so it matches new circuit boards. Its tricky but it can be done. I had mind done as I wasn't going to try lifting the old one down. and the new one up.

[Bwilson]

I did our 2004. Hardest thing was to get the new one up there. I also had to call DRV to get an explanation on the wiring change. Take off the shroud, 4 bolts and I believe 3 wiring connectors. Easy peasy!

[dmorse68]

Use this seal rather than the generic ones you buy on amazon or camping world. The reason is, those are constructed in sections and glued together, creating seams in the corners where rain and condensation water from the AC running can penetrate where the seams are. This manufacture cuts theirs from one solid piece of closed cell foam. Here’s the link: Steele Rubber Products RV Roof Mounted A/C, Heat Pump Gasket Kit - Sold and Priced by The Set 70-3905-207 https://www.amazon.com/dp/B07TW7QY16/ref=cm_sw_r_cp_api_i_LGtdFbN89TF9Y

[Seamus McShank]

Circuit boards are different from old AC unit to new ones. You also have to replace thermostat to the new style so it matches new circuit boards. Its tricky but it can be done. I had mind done as I wasn't going to try lifting the old one down. and the new one up.

My unit is '05 and may be on the way out. I can see that the thermostat would have to be replaced to match today's ac circuit boards, is the existing wiring ok or does it need to be replaced to match.
Seamus

[Walt]

Wiring is okay.

[Weahenz]

I've been using the BougeRV 2899BTU portable rv air conditioner (https://www.bougerv.com/products/2899btu-portable-air-conditioner) for a long time. It can run on both AC or DC power. It does not come with the battery for DC power. It comes with the power cord for the AC outlet and all the hoses for directing the air conditioning and also directing the exhaust. It's easy to operate by pressing the buttons to change the settings.