Basement A/C does not appear to be working on Ultimate Advantage

rowesort · 10-28-2009, 12:54 AM

Just got to Yuma Arizona the Temp is 91F and our basement a/c is not blowing cold air! A couple of days a ago everything was fine the radiator /cooloing unit is hot and I can hear the fan running, I think the compressor is cycling in and out but not as loud as normal. Any one got any ideas on where to look.

I will be giving the rad/ coolling unit a clean in the morning. Looks Ok though

McDuff · 10-28-2009, 09:55 AM

Are you plugged in? Thinking maybe low voltage...

KIX · 10-28-2009, 05:30 PM

Steve, have you checked the supply duct that goes up from the A/C to the roof supply plennum. Make sure the duct work is not leaking cold air.

If you need help getting the unit out of the coach for a tech email me and I'll give you my cell #. I've had mine out a couple of times.

Thudman · 10-28-2009, 08:49 PM

I was ready to have my basement unit pulled out because of poor cooling. I had already replaced two start capacitors (one was fried, preventing #1 compressor from coming online). Still wasn't cooling properly. But others on this forum convinced me to check the ducting coming out of the basement unit, and up in the rear cap area. Yup, that was it: there was a duct leak, shown below at the bulge (I'm on my back, looking up; rear cap is to the right).

The fix was to apply metal (NOT regular cloth) duct tape to seal the leak:

I used a 4 or 5 ft 1"x3" board to apply the metal tape:

It worked, and only cost pennies. I submit this only if you have a duct leak (and in the lower part of the duct). If it's something with the compressor, that's 'nother story.

Thudman

Navy Flier · 10-28-2009, 11:46 PM

Can we assume that you have checked for a clogged filter?

DAN L · 10-29-2009, 02:19 AM

check the start capacitors and the fan motor relays. they are under the panel accessed through the outside heat exchanger door. my fan motor relay smoked and nothing would work although it sounded like it was trying to start. if the #1 system has a fault, the #2 system will not start. it is possible to switch the wires of the #2 system components to the #1 components for troubleshooting.
the #1 system should run just fine by itself with the #2 system cb turned off, but not the other way around.

rowesort · 10-29-2009, 09:59 AM

Quote:

Originally Posted by Navy Flier

Can we assume that you have checked for a clogged filter?

Is there another filter other than the one in the bedroom ie return air filter under night stand cabinet?

AFChap · 10-29-2009, 03:12 PM

One filter ...mine is under the closet, some under bed or cabinets. Mine is a 14x20x1 paper type filter.

One very easy way to tell if the compressors are running ... need to be on 30a or generator power. Watch the amp meter on the EMS power panel. Set the temp 5 or more degrees below room temp. When the first compressor is running it will be pulling 17-18 amps. About two minutes after the first compressor kicks in, the second should kick in. (The outside blower stops briefly when the second compressor kicks in). When the second compressor is running in addition to the first, they will be pulling around 24 amps (of course, total amp reading depends on what else you are also running).

The vast majority of folks who have problems with the a/c unit have leaky ducts ...either the L where the duct exiting the unit turns upward behind the rear cap, or in a joint further up the cap. You should be able to detect these leaks with arms reaching up near the duct, feeling the outside of the rear cap on a warm day when the unit is running, or with a feather or piece of paper on a long stick up beside the duct behind the cap.

The second likely cause is one or both compressors not running due to burned start capacitors. When the start capacitor was burned out on my 2nd compressor, I could faintly hear it try to kick on several times before it would give up.

KIX · 10-29-2009, 08:15 PM

If you find that you need relays or starters or capacitors try US - Electronic Components Distributor | Newark.com Have your part number in hand. Usually very good prices.

rowesort · 10-31-2009, 11:58 PM

Thanks for all the suggestions, ran the generator and got only a 10 amp draw then it flashed to 31 Amps for micro second. Opened up the A/C cover and found a jumper wire on 2 insulated spade type connectors fried to a crisp, Made a new jumper and presto. Runs great.

Thanks again for the help!!