AC doesn't work, do I need to replace the whole thing?

[Cee Cee]

Good day, I have a 2007 cougar 276 rls 5th wheel that I purchased new in 2007. I traveled for work so I wasn't able to use but a few times. My Dad is going to bring it to Fort Rucker, Alabama where I am now, from the OC in California.
He says the air conditioner works but blows hot air and when he called local RV repair place, they have told him that it needs to be completely replaced. Is this true or is there a way to figure out what the issue is. My dad and i are mechanical but lack a little air conditioning 5th wheel knowledge. Any ideas, comments, suggestions would be greatly appreciated. thank you.

[chuckster57]

Welcome to the forum!
AC units in RVs aren't considered "serviceable" so if there is a problem with refrigerant or compressor, replacement is the normal repair. Labor should be no more than 2hrs. I did mine in 45 minutes.
There is a worksheet that Dometic uses but I can't link to it from my phone.

[hankpage]

What Chuck said is correct. (as usual ) But the a/c in my '07 takes almost 9 minutes before it comes on. (time delay to prevent short cycling ) If the fan is set to on, the unit will blow hot air for that 9 minutes before the compressor starts. Have your Dad check it again with the fan set to AUTO and give it some time. Many times I have thought mine has died and it just teases me for a while and then starts. :facepalm: Once it is running it cycles normally. It's worth a shot, Hank

[Cee Cee]

oh thank you so much to the both of you. i will have my Dad do exactly as you say and fingers crossed. if it doesnt turn cold, are we looking at replacing the whole unit, like the box on the roof? i am going to see if i can find that link you were speaking of.

[chuckster57]

Make sure you get the same brand that you currently have. The unit is self contained and sits on the roof.

Same brand makes a swap a walk in the park so to speak. Take off the ceiling grill and there will be a long bolt in each corner that holds the unit down against the roof. Wiring to unit should unplug/ plug into the control box mounted in the intake.

[dwall]

You might want to get a second opinion. It could be as simple as a $20 capacitor or a bad wire. Usually if compressor is bad you can hear it try to start and then kick out on overload. It's worth a try.


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[chuckster57]

If you have an amp gauge, just remove the ceiling plenum. Find the control box and open it up. Look for the A/C motor relay. It should have 110VAC going into it. Find the power wire from the relay to the roof (should be the same color as wire into the relay) NOT the ground or neutral. Clamp the meter on the LOAD side of the relay. Turn on the AC and it shouldn't go any higher than about 14A.

Capacitors aren't known for failing in RV AC units. Most common is loss of refrigerant, and compressor failure. HIGH amp draw is a quick down and dirty test.