A/C kicks "on" and "off" ?

I have A Dometic 15k BTU in my 30 LSBS Wildcat.
Just today I have noticed that my A/C while turned on would stop blowing cold air as if the thermostat had kicked in.
The problem is that the thermostat is set at around 70 and the trailer is for sure hotter than that.
I was wondering why the A/C would stop blowing cold air while it is still hot in the trailer?
I have been monitoring the voltage coming into the RV. It is 121 Volts. When the A/C is turned on, it will drop to like 115-117 volts, which is normal. The reason why I did that was to make sure the A/C iss indeed ceasing to blow cold air on and off...

Any advice, help would be helpful.

Thank you all!

Possibly low air flow thru evaporater causing Iceing and the Ice up switch is shutting down the compressor. Check for plugged filter blocked vents ETC.

Thanks for your reply onetonford.
There was nothing Iceing that I could notice.
The weird part of this is that the AC is working fine now at night.
I called the dealer who said it could be the compressor gone bad.
But how can the compressor has gone bad if it still kicks on and off.
It stays on for 4 minutes and then shuts off for 5 or 6 mins, then compressor kicks in again... repeating the cycle during the day.
The unit never stops blowing air, all it does is that it ceases to blow cold air when compressor ceases to work.
Could it be any safety shut off?
I am so far from home and dealer says "you have to stop by so we can take a look"... Usually a waste of time and money.
Thank you for your response again. if you think of anything else, please send it this way.
May God bless.

If it works at night, but not during the day, you might have the thermostat set too low. The A/C, trying to keep up, doesn't get a time to rest. Try setting it at about 75 or 78, and if it gets the temp down that low, gradually take it down some more. Is 70 your comfort zone?

Tater

Is the thermostat fan setting on auto or on. If its on, it will run even if the compressor isn't. Also check to see if one of the ceiling vents isn't blowing directly on the thermostat. And, like onetonford said, check the filter. A restricted air flow will cause that problem.

After all that, you may be low on freon. That will take a pro to diagnose and fix. It may require replacement of the unit. Not real sure, but I don't believe there are any fill ports on an RV AC. It's factory sealed.

Hope you get it figured out and it's something simple.

John

Dear Scruffy and Tater and John,
I have set the thermostat to 72 during the day. I feel that it stoped blowing cold air in intervals of 4-5 mins at time and then kicks on again. I will try setting it to 78, maybe 75 and slowly turn it down as it cools.

I have also set the Thermostat to "on" instead of "auto", and it will do the same thing. It blows cold air for a while then it stops blowing cold air... same thing...

I bought a window unit last night at Walmart. The worst investment made in my life.

Thanks for the help, it is helping out a lot.

Is it possible that your compressor has a slow leak and lost some refrigerant?

Also, try covering your thermostat so that no cold air can blow on it. See if the short cycling stops by doing so.

TC

Hi TC,
Thanks for your input. No signs of refrigerant leaks.
I have installed a window unit from Walmart that does keep the living area cool.
When I run the RV A/C when its already cool inside, the problem never comes back and the A/C works just fine.... BUT if I turn off the window unit and let the RV A/C run on its own, the symptoms come back and the cycling of on and off resumes... I am out of options? They wanted to charge me 1300 bucks for a new unit from a dealer in the next town. I am so disappointed. Any other ideas? Thanks again.

It's much cheaper to replace the thermostat. I would start there.

John

I sure hope you can find a solution that won't cost you a whole new unit. Wow! $1300 - that's awfully expensive.

Best of luck in finding a solution.

Tater

Since I am a newbie ( as you can tell...) how much do you think a unit should cost in a fair price range? My unit is a 15 k BTU, by Dometic with no heat strip. Thanks again Tater!

I had same problem. AC would work fine at night when cool but not during the day when hot. Compressor was fried.

donarumma.

Camping World has a 15,000 btu Coleman for less than $1000.... less than $800 if you are a member of their President's Club (which is about $20 for a year). I don't think they are hard to install. If you have a CW nearby, they will install. Shipping might get you if you aren't near a CW.

Tater

Thank you all.

An update on the AC issue. I have taken my Rv to the dealer to inspect the AC unit since it is under warranty. They said they could not find anything with it and charged me 150 bucks for that. I called the warranty company who said that if the shop working on my RV can not come up with a real issue, they can not fix it. Since I work out of my RV I did not have time to take to a diferent shop. I must mention that when they monitored my AC the weather outside was around 75, so the AC worked fine and the compressor did not do the " on and off" thing. I am so upset because I am now back at work with my RV 300 miles from the dealer and the problems are still happening. I have bought a 14k BTU portable AC unit from Costco and have it mounted in the living area. It does an ok job but the bedroom get no cooling.

**Since I am here, I was wondering if anyone would know or be able to help me out if it is ok for me to drill a 5" hole for the venting hose of this portable Ac unit on the wall of my RV. I hate having the window cracked open and the hose taking so much room. Thank you so much again for any help!

carcamano,
we have the same issue with our AC. Did you ever find anything wrong??

I believe that the AC is just taking a break. We live in our 5th wheel full-time. The summers can get pretty hot, 100+. The AC unit will run constantly trying to catch up, but it can't. An AC unit is only supposed to cool the air a few degrees below the temperature outside. Even RVs with 2 units can only cool the inside temperature about 20 degrees below outside temp. So if it is 95 outside, it will only get down to 75 inside, and that is assuming that you keep the doors closed, (not constantly running in and out).

We bought a portable AC unit from Walmart (didn't like), so we tried another from Lowe's. It is not a window unit. It is a portable floor unit. We vent it out the window beside our dinette in the slide. We opened the window (it slides to left) and the screen. My husband cut a piece of plexiglass the of the opening. He then cut a hole in the plexiglass to accomodate the vent hose. He also attached a dryer vent cover on the outside to prevent water from coming in during bad rain storms. (I can post pics if you are interested.) You may have already figured all this out.

Anyway, during the hot days we run both. The main unit still runs almost constantly, but then at night we turn the main unit off to give it a rest, and the run the portable unit to keep us cool. (We also use a floor fan to help circulate the air in to our bedroom and to hide outside noise.

I don't belive our main unit cycles in such short increments as you described, but is still does cycle off and on some when running constantly. We were getting a little odor out of the vents this summer. My husband climbed on the roof and had to clean out the drain pan. He said it was at a wrong angle preventing it from draining properly and it was puddling and getting stagnate.

Hope this helps....Please let me know what you find out on yours in case I'm mislead on our AC.

Julie