new air conditioner or repair 10 year old unit

[rockwind1]

greetings. i have a 2007 attitude FSAKG 34' fifth wheel. man, i am always working on this thing but it has 2 ac's, one in the master which is a 12,500 i am pretty sure and the "main" one which is a 15,000 btu unit. the main one has taken a dump, i think it is toast, although i am not a air cond tech, have the guages though but the rv shops here in vegas are pretty cut throat. I would be better of having ISIS work on it. between driving the trailer down to ISIS headquarters, having them fix it for no doubt in the hundreds of $, i can get a new unit and put it on myself for 5, which seems really easy (except for getting it on the roof)

so my question is for those who have experienced a similiar problem

are the newer models a lot better and more efficient than the 10 year old models?
is it worth getting repairs (assume the worst like the pump is bad)?

is it as easy as it seems?

thanks in advance for any helpful responses. (fyi, i asked on another forum also)

[rockwind1]

the t stat only operates one unit, the main one i am working on

well, that worked great! put on the supco spp6 from the other unit and it started right up. was pulling about 14 amps as it was running. the fan pulls about 3 amps so the compressor was pulling 11, and the compressor RLA is 10.7 so that should be good, right? it didn't seem to be as cold of air as i would have liked though.

any thoughts on what i should do with the Dometic A/C WSX-5 Motor Starter that is on the old start capacitor? should i keep it on there?

[Ivylog]

If both units use one Tstat with two zones a new unit will not work with it unless you buy an additional convert board...$150.

[j-d]

Your compressor should have a label showing Running Amps and Locked Rotor Amps/LRA. Our home A/C would show LRA on my clamp meter if the Run Capacitor was bad. With a new capacitor, it started normally and fell into the Running Amps range. If you have a good capacitor and the compressor draws LRA, it's probably shot. We had a case where the compressor wouldn't start. I suggested going to the roof, A/C shroud off, and be ready with a rubber mallet when a helper turned the A/C on. Smack compressor with mallet right when the power came on. This has to be quick, since the compressor has a thermal overload inside and will disconnect the power if it stays at LRA. It worked! I do not know for how long it worked.

[Chris_Bryant]

Either start cap/ptc combo will work on either a/c- the Coleman should be 88-108mfd as well. Also look closely at the run capacitor.

[rockwind1]

so, the blower fan turns on and runs fine, running amps at 2.5 ish. however, i had my setting at 40 amps and the compressor motor went over that when trying to start because it said overload. then i could hear it sort of humming, like it was still trying to do something. anyway, the start capacitor is a NGM88-108 MFD 50-60 HZ 165 VAC MADE IN MEXICO IN APRIL 2006

although it is not tripping the 20 amp breaker (piggy back style breaker) it would seem like it should. any thoughts?

ANYTHOUGHTS ON HOW LONG START CAPACITORS LAST, IT ALSO HAS A Dometic A/C WSX-5 Motor Starter STUCK ON THE TOP OF THE CAPACITOR.

what is the general consensus of using the start capacitor from my 13,500 btu dometic unit jsut for a quick "see if it works" test?
the ac unit that is not working is a rvp rv products division of airxcel, inc.

[dougrainer]

MEXICOWANDERER wrote:
This is a "I want to learn" question 🙂

What type of freon did they use back then?

The OLDER units used Freon 22. The Newer units do NOT use Freon. They use 410a. Normally I would not nitpick(Freon versus 410a), but YOU usually nitpick on some issues:B They phased out 22 about 6 to 8 years ago. Doug

[rockwind1]

thanks everyone, i didn't know that about no ports. kinda used to residential and auto ac stuff, mostly auto. and i do have a inductive amp reader, a couple years ago i checked the start up and running amps for both my units cause i was going the 2 honda eu2000 route to run one of them and i was seeing if the smaller unit would work with just one, it didn't , but i will look a little bit closer at it today.

[MEXICOWANDERER]

This is a "I want to learn" question 🙂

What type of freon did they use back then?

[time2roll]

I would repair external components.

However motor, compressor, leaks etc to the main unit I would just replace the whole thing at even five years. Get a high efficiency unit the size you need and review the ducting connections during install.

[j-d]

If you're handy and have a little time, BigKatuna and MattColie have the plan I follow. Clean, oil, test... Clean the Coils and Blower, Oil the Motor, Test or Swap the Capacitors.

I'm blessed to have a DVOM that tests capacitors. With that and my cheap Harbor Fright AC Only Ammeter (plus one of their little free DVOM's) I can do a goodly amount of troubleshooting. I replaced the blower motor in ours (Coleman Mach 15) for about $100. It's never needed capacitors, but I keep spares for those on board. Anything "Sealed", the coils, compressor, even lines, I'd replace the unit.

[parkmanaa]

I would replace it. I live just outside of Houston, and here we have one of the largest, and least expensive, RV parts houses in the country.
PPL RV Parts.
Bought a ducted 13,500 upper and lower unit from them last month for, after taxes, just under $600.
I believe they ship anywhere in the country for a very reasonable rate.

Installing a rooftop is remarkably easy, biggest job is getting old one to ground and new one to roof. I'm lucky there, we have a tractor with front-end loader that handles it quite easily. I have seen 2 men take a unit up ladders and didn't seem too bad. Hooking up is no challenge even for an amateur.

I personally would not spend several hundred dollars with a A/C tech when I can get the whole package for around $600.

[Matt_Colie]

Rock,

Work on Big Katuma's plan. Check out the capacitors and other easy stuff like oiling the fan motor. If the refrigeration side it dead, it is rarely effective to repair same and it takes a whole lot more the gauges that you can't hook on because there are no access fittings.

Matt

[Big_Katuna]

Well if you say you are handy, take the cowl off, find where the wires from the motor go into the sheet metal and take off that cover as that is where the caps and the PCTR is.

You often see dead electron guts if a cap blew up or the PTCR blew up.

They are under $20. If you are not hearing any humming, the compressor isnt starting.

[ctilsie242]

If it is 10+ old, it may be using Freon which is ever harder to get. RV units are sealed from the factory. At best, you can get someone to install a vampiric tap so more refrigerant can be added... but those will eventually leak anyway.

Realistically, I'd replace the unit with a new one. Newer models are definitely more efficient, and you will have a warranty for a year or two as well.