I have an older Jamboree I am breathing new life into and cost is a concern. Our in-dash air conditioner is dead and I am mulling over converting it to R134A. However, I have seen some posts comment that the dash A/C is nowhere near enough to cool the RV on hot days and that it makes more sense to just run the gen. set and rooftop A/C.If you had a 1983 Jamboree (26'), would you bother to repair/convert the in-dash A/C to R134A, or just forget about it and use the rooftop any time you wanted to cool the rig down?Jose

Kind of a tough call. Its true that the dash air won't cool the entire coach but it makes a difference esp in the front 8-10 feet when driving. Not to mention the comfort level of the driver and front seat passenger. On really hot driving days you'll want(need?) both cab and overhead air to stay cool.Personally I'd want the cab air to work but it all comes down to how much you want to spend.Another thing to consider is how much you'll be driving versus sitting. If you take short trips or not many trips, maybe you can sweat it out with no cab air.If you take longer or many trips, also consider that the extra fuel you use to run the generator (maybe 1/2 gallon per hour) may add up over time to more than the cost of the cab AC switch?

Which system do you have, Jose - The "factory" with a cylindrical compressor or the "dealer" with one that looks like a mower engine?We had "dealer" and though it was a pain in several ways, it blew COLD after conversion and I would not have wanted to do without it. Our Holiday on 83 E350 was 24-ft but we never ran roof air on the road. Only the dash and it cooled the whole rig. Vehicle A/C is rated in the 20,000 range and your rooftop is probably 13,500. Whenever we try to run roof air for travel, it just doesn't satisfy. You want the air in your face, not behind your back.You need new oil, the 134 of course, new drier, fittings and label, plus a HPCO switch (High Pressure Cut Off). No need to replace hoses or O-rings unless they're failing. If it's factory, new orifice tube and new LPCO switch (or adjust the old one). If dealer, new expansion valve.Either way don't overcharge. Start at 60% of OEM R12 charge and see what it does. Your low side may wind up low, but if you try to raise it you may find the high side goes too high. Conversions tend to jump into excess high side pressure.

I'd consider repairing it and recharging with R12. It should cool the cab fine, but asking it to cool the house is asking too much.

Good point, paul. He'd have to get somebody with a license to evac and charge it, but the periperals to convert aren't cheap. There's a ton of R12 out there, and meanwhile the price of 134 has climbed. Diff might not be too bad. Just do something before the other shoe falls. R134A is "now" considered harmful. Gee wow. R12 banned then R22 was accused but never convicted. Banned anyway.

j-d : I have the "dealer" York compressor, not the factory cylindrical. I pushed the Schrader on the fill side and I get nothing. Seems like its totally empty. The in-dash A/C is 20K BTU? Wow ...... Ok, then. It sounds like I should get hold of a vacuum pump and see if my R12 system holds vacuum. If so, then I will hot-wire the clutch so I can confirm it is working. If that is a go, then I will have my buddy (HVAC dude) get me some R12 and we will re-charge.Thanks for the feedback folks. Will update this thread as I make progress.Jose

In-dash air conditioner - Worth converting or fixing?

46 Replies

DaHose
Explorer
Jul 07, 2014
Thanks j-d. Your help along the way made it possible. Now we have a roadmap for anyone else who might want to change their compressor in the future.

Jose
j-d
Explorer II
Jul 06, 2014
Jose did a very skillful job with the conversion and the documentation! I wanted to do that on one we had but I let a critical part get away. Also, I thought it'd need welding and I don't weld. There used to be compressor conversion brackets, don't know if I can still find them.
The real challenge is actually the compressor hose ports.
Again, Great Job, Jose!
DaHose
Explorer
Jul 06, 2014
Thanks for the tip, Dusty. I'll be sure to leave the slider in defrost mode at all times.

I changed the refrigerant to R12A, Hank. It cools great with no additional modification, takes less product to charge the system and doesn't even need vacuum to charge. Since the bulk of the system components are at the open front of the engine bay (not near the headers) I am comfortable running an isobutane based refrigerant. On my M6, the A/C lines run all along the "hot as hades" headers. I am NOT comfortable running R12A in that case.

Jose
JaxDad
Explorer III
Jul 06, 2014
snowdance wrote:
noe-place wrote:
Dash unit won't cool beyond the pilot/co-pilot area. DW runs the genny and roof AC when things get too hot. Let your wallet make the decision for you.

The dash AC will cool the complete rig if you open a roof vent or some thing near the rear of the rig so the air can go thru. It is air coming in and if it has no place to go it will stay right there and do only the cab area. If you have roof vent covers while going down the road with the vent open some it will form a vacuum amd pull the air from the cab AC thru the complete rig. Our complete rig stays cool even in 114 degree temps. Roof AC will not do as well.

Ditto!

While rolling down the highway my dash unit will cool the whole rig as well or better (it's higher got higher cooling capacity, but a smaller fan) than the rooftop unit will.
Hank85713
Explorer
Jul 06, 2014
we converted an R12 system to 134 in a small van we had at one time. Nothing but a nightmare since the 134 requires a larger evaporator and other things. The place we had it installed went thru 2 compressors and 1 new evaporator before finally recommending going back to R12.

So if you are really researching plan on replacing more than just the juice. I am sure there are some that will say it works but just how well they never say. Just my Opinion however based on experience.
Dusty_R
Explorer
Jul 06, 2014
When the sun shines on the windshield, it heats the glass and the glass radiates infrared heat into the mh. To counteract this turn your defrosters on. The AC runs when the defroster is on, this will cool the windshield.

Dusty
DaHose
Explorer
Jul 06, 2014
Hello, everyone. I have a final update to this post. I have completed my dash A/C repair/conversion and documented it. Below is a link to the document.

York to Nippondenso A/C Compressor Conversion

In a nutshell. The Nippondenso 6P compressor is a GREAT upgrade. I also charged it with R12A and it performs really well.

Hope the document is helpful to someone, someday. :)

Jose
Dastagg
Explorer
Aug 24, 2013
When my dash unit quit cooling, I tried using house ac and gen set with fan blowing in cab area. Way too uncomfortable in Southeast Texas heat. Got it fixed and now only need cab ac while traveling and MH is cooled some when stopped. Maybe not to set temp in MH, but dash unit cools pretty good while traveling. Definately would fix it. Past experience in heat requires it for me!
crawford
Explorer
Aug 23, 2013
Sounds like way to many experts in AC repairs to me and retro fits kits to me. LOL.
snowdance
Explorer
Aug 23, 2013
noe-place wrote:

Hey that's interesting. Do you have your AC set on re-circulate position when doing this?

If you set your AC on re-circulate it does not bring in more air so air inside moves only in the cab area.

If you bring in out side air it will move thru the rig. In a lot of ways air acts a lot like water. If you keep adding air to the inside it flows thru. That keeps the whole rig warm or cool. Hard part is trying to get people to open a rear vent in cool or hot weather because they think the out side air will come in but if you keep warm or cool air coming in thru the cab heater/AC it will only exit the rig. And it will exit at the rear so goes thru the rig. Faster you run the heater/AC fan the faster it heats/Cools the rig. Most Cab AC's are some where around 50,000 btu. Most roof ACs are about 1300-1500 btu.