KSDP 3910 Front roof AC not cooling well

[mottybri]

Hi! We took the coach to the dealer and told them the front roof mount AC was not cooling well, while the rear would freeze you out. It was 88 degrees outside and the front would only cool to 80 degrees. They told us it was working fine, and it was because of the area it had to cool, it would not get as cold as the rear. I can feel a big difference in the temperature of the air coming from the rear and front units, the rear air is really cold, while the front is about half as cool. If it had been 98 degrees I guess 90 degrees is the best I will get, and that won't do. Do you guys have any cooling problems? The last coach we had did the same thing, and Camping World put a new unit on, and it would get really cold with the new unit. What do you think? There is no way we can enjoy our coach if it won't cool off. I read as many posts about AC cooling, but could not find any answers. The filters are clean, is there anything else I can check? They did say we could close off some of the rear vents to force more air to the front, but I remember reading somewhere not to close the vents, but adjust the thermostat, that closing vents could damage the AC unit.

[mottybri]

Hi! We took the coach to the dealer and told them the front roof mount AC was not cooling well, while the rear would freeze you out. It was 88 degrees outside and the front would only cool to 80 degrees. They told us it was working fine, and it was because of the area it had to cool, it would not get as cold as the rear. I can feel a big difference in the temperature of the air coming from the rear and front units, the rear air is really cold, while the front is about half as cool. If it had been 98 degrees I guess 90 degrees is the best I will get, and that won't do. Do you guys have any cooling problems? The last coach we had did the same thing, and Camping World put a new unit on, and it would get really cold with the new unit. What do you think? There is no way we can enjoy our coach if it won't cool off. I read as many posts about AC cooling, but could not find any answers. The filters are clean, is there anything else I can check? They did say we could close off some of the rear vents to force more air to the front, but I remember reading somewhere not to close the vents, but adjust the thermostat, that closing vents could damage the AC unit.

[Harm]

Mottybri: Our 2006 DSDP is exactly the same as you describe. We put a fan on the floor of the bedroom to blow A/C out into the living room and it really makes quite a difference. Not the perfect fix after spending the big bucks but it works.

[soricobob]

I would say that the next thing you should check is a better dealer.

[GaryKD]

Yep, that is what we get with an 05 KSDP. We have the same coach. I set the thermostat for a difference of 2 to 4 degrees with the rear unit being set to the lower temp. This allows both units to opperate at about the same time and help keep the entire coach cool. Do not go by the reading on the thermostat. Have an independent way of measuring the rear and front temp. However you measure the temp. do not fasten the measuring device to an outside wall.

If you are parked so the PM sun is on the front of the coach, forget keeping the front cool unless you install a suplemental shield for the windshield.

The reverse of this post is true when heating the coach.

Heating or cooling, some method of covering the windshield is needed. I have the screens by MCD.

[mottybri]

I was really hoping you guys would tell me your coaches are cooling fine, and I then I could get my repaired, (at a different dealer) but if this is all it will do, I guess I will do what you suggested, with the fan and the windshield cover. I agree with you Harm, for the money you would think they would work much better. Thanks GaryKD, I will use some type of shield for the front window. I may still try another repair center next spring. I hate to think how hot it will get inside, next summer. Thanks again, I appreciate your responses.

[Dav5942]

Sitting here in Florida(still 90 degrees). Although we have three ACs(2-15M,1-13.5M) only one has been running(with the garage door shut and the third AC turned off). Have the front AC set at 76 and while waxing the roof today it only came on periodically(maybe five minutes on, ten off). The mid AC never came on. We are facing north which might help some.

["007"]

If you can find a "good" dealer that knows how to cut into duct system he could add another vent opening return and cool that may help.

[Norm Payne]

Take a temperature reading from the closest return duct to the air conditioner and a reading from the closest outlet air duct. There should be at least a 20 degree difference. Let the air conditioner run at least fifteen minutes before taking readings. If it is less than 20 degrees the air conditioner is not cooling properly, but if it is 20 degrees or more difference you have a circulation problem.

Using a thermometer is the only way to check an air conditioner and the technician should have given you the readings. If he did not explain how he tested the air conditioner and give you the reading I suggest you find a qualified technician.

The large single pane windshield allows more heat into the front than you get in the rear so you need more outlets in the front. I had Newmar install one extra outlet between the front two outlets and it made a world of difference. It is a simple job and I would have installed the outlet myself, but I was at Newmar and let them do the job.

[Route 66]

Thanks to Norm's suggestion, I too had Newmar install an extra supply and return outlet all the way forward.

It helped.

Closing off vents may not be beneficial, as the AC requires a certain amount of airflow across the cooling coils for efficiency.

If too much air flow is restricted, the coils may freeze up.

[OpaRon]

FORGET the dealer and find an independent repair shop authorized by your heat pump manufacturer. I was bounced around for almost TWO years trying to get my front unit fixed by my selling dealer. I finally took it across town to an authorized repair shop and it took a competent technian about 30 minutes to tell me it needed to be replaced (which my wife told me almost a year ago!) Two hours later I had a new unit in the coach and it works great! Just like it's supposed to work. I assume you have the 3 year Newmar warranty (05 being the last year for such) which means you must be getting close, so I wouldn't delay in getting Newmar or the heat pump mfgr to authorize your going to another repair facility.
OpaRon
2005 DSDP 4009
2002 4Runer Toad
1 wife
1 dog
Finally fulltiming!

[mottybri]

Thanks, Norm, I will try taking the temp. like you said and if there is a problem I will do as OpaRon suggested and find an independent repair shop. When you say you were at Newmar, are you speaking of the Newmar factory? I am not sure about some of the people that work on these coaches, I had rather take it back to the factory if possible..

[Norm Payne]

The two parallel air ducts run the full length of the motorhome and you can add as many returns and outlets as you want. I think they cost about $5-$8 at Newmar and any Newmar dealer can order them for you.

Just draw a line between two existing ducts and center the new one on the line. Cut a circular hole and mount the outlet with four screws and put a little clean sealant around the inside just like the others.

Adding just one cooling outlet in the front of my Dutch Star made a big difference in cooling the front in hot weather.

When I was at the Newmar International Rally in Gillette, WY in 2000 there were a lot of owners complaining about their air conditioners not cooling enough and freezing up due to low air flow. I believe through the 1999 models Newmar only installed about six cooling vents. Newmar technicians made the rounds and asked if anyone wanted extra vents and it only took them about five minutes in each motorhome.

[mottybri]

Great, thanks, I will keep that in mind when I am near a Newmar dealer, it will most likely be next summer before I can get there. I believe the nearest one to me is 200 miles or more and we are about to settle in for the winter. Does Newmar have a rally every year, and is it held in different locations?