QBill, I have a 1994 Pace Arrow with a Duo-Therm Air conditioner. I’m having a problem with the air-conditioner failing to cool when I have the foam filter in place in the ceiling assembly. If I remove the foam filter the air-conditioner cools just fine. It’s getting into summer and I will need the air-conditioner and funds are limited. I appreciate your help!

Thanks, John 

A– John, I don’t think that I have enough information to diagnose exactly what’s going on with your air conditioner. I want to help and I will do what I can to best advise you. One thing that you don’t want to do is run the air conditioner without the return air filter as the evaporator will eventually get clogged with dirt, dust and other contaminants. Does the fan completely shut down or does it sound like it slows way down to a low speed? Duo Therm air-conditioners in the 90s had a propensity for the evaporator to frost or freeze over. Once the evaporator freezes over, there is no cooling taking place as the fan cannot pull return air through the evaporator. Later model air conditioners utilize an evaporator freeze sensor that helps prevent freezer over. Run the air conditioner with the filter until it stops cooling unit. Remove the return air filter and grill assembly, look up into the cavity with a bright flashlight and see if the evaporator is covered with ice. Depending on whether the evaporator is frozen or not frozen will be part of the diagnosis and of course, different types of repair.

QWe have a 2002 Airstream trailer with a rain leak that shows up over the wing window on the curb side of the trailer. I’ve had two separate dealerships attempt to stop the leak to no avail. Any suggestions? We look forward to learning from you each month.

Andrew and Jennifer

A– Yes, Rain leaks in the Airstream trailers are notoriously difficult to find. With all of the seams, rivets and windows, it is a challenge to see where the rainwater may be coming in. Due to the curvature of the roof coming down over the edge of the roof line and becoming the siding, it’s very difficult to just start putting sealant all over the place making it unsightly. The first place that I would look would be the marker lights up over the wing window and the center window. The lenses over the lights can trap water and over a period of time, the water will seep through the screws or rivets that hold them in the place. Caulking alone around the outside of the light does not do the trick. Remove the lenses and the screws to all of the front clearance lights, fill the holes with sealant and put the screws back in the place adding a little bit of sealant over the screw heads. Before you put the lenses back, on add some caulking to the hole that the positive wire goes through into the shell of the trailer as water can leak through there as well.

QBill, I have read about a refrigerator control device made by ARP, a type of control to help prevent the refrigerator from overheating or catching on fire. I’m a little bit leery of advertised products, but this sounds like it could be a lifesaver for our refrigerator in our 2010 motorhome. Are you familiar with this product? Have you ever installed one? Does it work?

Thank you for your help, Jason

A– I actually installed one of the first ARP’s that was manufactured several years ago, and yes, they can be a lifesaver for your refrigerator. The device has a temperature sensor it that attaches to the boiler tube on the back of your cooling unit and wires into the system. Whenever the boiler temperature rises above the set temperature it will actually shut the refrigerator down protecting it from overheating. When the refrigerators boiler tube cools back down, the refrigerator will come back on automatically. It does not take much of an angle beyond level for the boiler tube temperature to rise to an unsafe level. Mountain driving, stopping for lunch when the parking lot seems level enough, as well as campsites that you may only stay one night without leveling the rig may cause high temps. As in a lot of appliances and mechanical devices in this world heat is their biggest enemy. I believe all refrigerator manufacturers should use a device like this to prevent the refrigerator from self-destructing as well as safety factor. There is no question that the safety of you, your pets or children are high on the list.

QWhat your thoughts on the MORryde IS suspension and disc brakes? We are looking to upgrade our 2016 5th wheel largely because we can’t stand the way it rides with the leaf spring suspension, not to mention the Electric brakes are lousy and barely stop our big rig.

A– The MORryde independent suspension or IS is a wonderful suspension. The ride is smooth and can be adjusted to raise the height of the trailer if need be. The only drawback is it is rather expensive and difficult to find an installation center. Another drawback comes when one of the parts break- it takes about two weeks to have a replacement part shipped to you. As far as disc brakes, they are absolutely a must for large RVs as the stopping power and improved safety is a huge safety factor. In some cases the stopping distance can be literally cut in half. I personally would never own a trailer without disc brakes. For suspension Systems, look at Kelderman Air ride suspension systems. The airbag suspension coupled with gas shocks rivals the ride of the MORryde IS at a better price and more reliable, and spare parts can be attained quickly. With the air ride suspension the trailer height can be adjusted at any time.

Q I noticed when I was working on my motorhome the converter is getting hot. I see that there is a small cooling fan at one end of the converter and I have never heard the fan run to cool it down. Is the fan supposed to run intermittently or does it run continuously?

Cheers, Alex 

A– Hi, this is a great question about the converter. Converter’s are out of sight out of mind until they ceased to function whether it’s from a component failing out or the fan not keeping it cool. The fan is normally intermittent and only comes on when the interior of the converter gets to a certain temperature. There’s no way of telling whether the fan is working or not without hearing it run of course, normally they are hidden so you can’t hear them run. There is no way to repair the fan if it’s not functioning and eventually the converter will cease to function and you will need a new one.

-RV Bill’s Cool Tip-

Most modern air conditioning units are equipped with a wall thermostat that has either an automatic or continuous cooling cycle switch. By leaving the thermostat in the “on” or continuous position, the fan will circulate cool air while the compressor cycles on and off, making the system much more efficient.

Categories: Ask RV Bill