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StrokerAce · 04-17-2012, 07:27 AM

Hello all. New to this site so need some help. I have a 2004 Coachman Cascade DLX 27RLS with a Duo Therm A/C unit. This was the first time out this past weekend to Arrowhead Campgrounds in Marianna Florida. We live in Panama City so not to far to go. The nights were cool but during the day got a little warm. Turned A/C on and no cool air. Bought a fan from local Wally World to get us through the weekend. Got home and started to trouble shoot it. All looks good on top of camper after pulling cover off roof unit. No leaks of freon on tubing. Think that one of the capacitors might be bad. Fan works, thermastat slide bar when you slide it down to a cooler temp, fan comes on, but compressor not kicking in. Think it might possible be a "Run Capacitor, Hard Start Kit or an Overload Proctor". Got to be at work at Tyndall AFB by 9:00 so need to put cover back on because of weather this afternoon. Any thoughts on how to check or what ot check?

Thanks
StrokerAce

jlfbatonrg · 04-17-2012, 09:43 AM

Sounds to me like the start capacitor might be bad. There should be a control box on the unit somewhere. If you open it up there will be up to 3 capacitors. There may be a wiring diagram on the inside of the control box. If one of the caps is bad, it will be burnt and obvious. You should be able to get a hard start capacitor kit from a local RV shop. Hopes this helps.

Jim

cherokee37g · 04-17-2012, 12:32 PM

I had the same problem last year with a duo therm a/c on my 2004 camper. The start capacitor was the obvious place to look first but....long story short, turns out all it took was to reach inside the cover with someting like an un-bent coat hanger and give the fan blades a push to get them going. That's all it took and we were in business. As long as it was run at least every 2 weeks it would start without any help.

I'm led to believe that duo-therms from around 2004 are prone to "sticky" shafts on the fan motors. Eventually I will replace either the motor or the entire a/c but until then I'll keep poking it with a stick.

StrokerAce · 04-17-2012, 06:06 PM

Thanks Jim over in Baton Rouge. Attack trained killer Shi-Tzu's? We have one that is 3 years and he is still a terror! But loving. He's a mama's dog. But back to the question. The fan motor turns freely and still has low and high speed off of the thermastat. So no problem there. So you seem to think that the hard start kit will start the compressor a working? Never been up on camper roof while it was working but don't see that "surge" in the lights inside when it kicks on. How will I know if that will and does fix it? Will I be able to hear the compressor running (?) from the ground?

Thanks again for your response

jlfbatonrg · 04-18-2012, 09:32 AM

Ha Ha, sounds like our two dogs. Sophie is pure bred and Jake is a pound dog at least 50% Shi-Tzu. They are both about 3 years old. I call them attack trained because if they get hold of you they'll lick you to death.

As to the compressor issue. I'm not familiar with your unit but all the units I've been involved with always start the fan motor first. A few seconds later the compressor will kick in. You can usually hear the compressor come on, and should feel the air getting cooler fairly quickly after the compressor kicks in. If the compressor kicks in and the air doesn't get considerably cooler I would suspect a Freon leak somewhere in the system (not good news). If the compressor does not come on, the 3 most likely problems in my opinion are an open 120V circuit breaker for the AC, the low pressure safety switch is not letting the compressor come on, or the compressor start capacitor. The breaker is easy to determine, and the start capacitor if fairly easy. If you open the control box for the AC, you should see the capacitors. If one is bad, it will almost surely be burnt, split, leaking, etc. When you open the control box there is a good possibility there will be a curcuit diagram inside. You can test the low pressure switch by bypassing it. If the compressor starts then the issue will be the low pressure switch or no Freon. Your unit is new enough, it might have come with a hard start kit. I just replaced a hard start kit for a friend that had in fact "fried" the hard start delay circuit, not the capacitor. Once you open the control box, you should be able to determine what's wrong if it's an electrical problem. Let me know what you find, and if I can be of any more assistance.

Jim

StrokerAce · 04-19-2012, 10:25 PM

Just order last night a Hard Start Kit. Replied to your email and iRV2.com didn't let it go through to you. But thats ok. Will let you know how it turns out when it comes in. I hope that the Hard Start Kit is all it is. Will checkout other things you told me about this weekend. Sounds like you might be on the right track. Hope it work! Thanks.

StrokeAce

jlfbatonrg · 04-20-2012, 08:29 PM

StrokerAce,

Good luck. Let me know how you make out. I'm interested in how you make out.

Jim

shoreco · 04-20-2012, 08:44 PM

Last year, one of my two ac's stopped cooling...

Went up top, took the covers off both and did a visual inspection...

The run capacitor on the broken unit had this snake like thing hanging off it (it was cracked and the inside ouzed out)

Bought a new one from PPL for $45 and all is good...

StrokerAce · 04-21-2012, 02:11 PM

Well it quit raining long enough to change the Hard Start Kit and it still is doing the same thing. Fan starts when the thermastat is turned down but still not cooling. Just can't seem to get the compressor to come on. When the compressor comes on in our camper, you get a surge in the overhead lights when it comes on. But not this time. Well that was a waste of $28.00. Anyone got another ideas? Discontected the wires and checked what I think is the "Load Protector" that is in the top of the compressor with a digital meter and it read "open" with no power running to it. So what now? What makes the compressor? HELP! LOL!

StrokerAce · 04-22-2012, 06:44 AM

Run capacitor looks good. Might even think about changing it. But if I had a freon link also, somewhere I would find traces of the oil that is in freon also. But have not found any of that either. Thank you your post.

jlfbatonrg · 04-22-2012, 09:30 AM

StrokerAce,

I'm assuming from your post that the original start capacitor looked OK, when you opened the control box. Did you check for 120V at the compressor start cap?If no voltage there, did you find a schematic in the control box? If so, did you trace the circuit up to the compressor start cap looking for a loss of voltage? Did you locate the low pressure switch if it has one and check for 120V? Sounds to me like you aren't feeding the compressor any volts, so it isn't coming on. see if you can find where the voltage stops.

Jim

hometool · 04-22-2012, 09:54 AM

i would try bypassing that load protecter it has to be closed for the compressor to run it is an auto reset cktbracker and thay can and do fail open

StrokerAce · 04-28-2012, 06:09 AM

Quote:

Originally Posted by jlfbatonrg

StrokerAce,

I'm assuming from your post that the original start capacitor looked OK, when you opened the control box. Did you check for 120V at the compressor start cap?If no voltage there, did you find a schematic in the control box? If so, did you trace the circuit up to the compressor start cap looking for a loss of voltage? Did you locate the low pressure switch if it has one and check for 120V? Sounds to me like you aren't feeding the compressor any volts, so it isn't coming on. see if you can find where the voltage stops.

Jim

Didn't get a chance to work on it last week because of work. But did find a wiring schematic online when I went to "Duo Therm A/C by Dometic" and found it. I think that it's the blue/white stripe. But will checkand let you all know. Just wondering if I might be wasting my time and the A/C unit is bad. But with the prices of "units" and what what shop labor is, you are looking at a big slice of your paycheck to get it looked at and new one installed. Good old shade tree mechanic's is what I say! LOL! Will let you know what I find.

StrokerAce

StrokerAce · 04-28-2012, 06:12 AM

Quote:

Originally Posted by hometool

i would try bypassing that load protecter it has to be closed for the compressor to run it is an auto reset cktbracker and thay can and do fail open

Will try that also Hometool. I guess that is like "jumping" across the low pressure switch on a car to fill it up with freon. I don't think that there is a low pressure switch on this unit to don that to. But will try that. Thank!

StrokerAce