I agree with Steve, if your AC unit coils have not been cleaned since the unit was new, odds are high they are very dirty and that can rob the efficiency of the unit. Both the inside coil and the outside could need to be cleaned if your has made it to this point.
Here is a post on how to clean them, this may or may not be doable in your case short of taking it to a dealer. http://www.sunlineclub.com/forums/f7...ics-10405.html
That said there are a few things that may help.
Run the unit on Hi. Running medium or low lowers the fan speed and my not clear out the ice buildup. Running Hi, this helps overcome this.
The windows, these allow a great deal of heat in. In the lumber yard they sell a product called "Reflect-ix" Reflectix - Insulation - Â*The Home Depot
It comes in different sizes and lengths. By putting this on the inside of the widows on the sunny side of the camper, it can help reflect out the heat. May use them cold weather camping to keep heat in but they work both ways.
The demand on the AC unit is a lot in time of high heat. The dirty AC makes the problem worse, but it is still an issue on a clean one, just not as bad.
I do not know of a fast fix for your weekend. The Reflectix is about the cheapest and it will help, how much I do not know.
LG does now make small portable AC units. While and option, it is not a cheap one.
LG portable-air-conditioner LP0815WNR | LG Electronics US
Sadly, you can buy a new roof unit for about the same money less installation. My son one of these for his pop up and it worked pretty good. But he had nothing and did not want to cut a hole in hi PU roof.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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