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Mouseproofing Your RV

Originally Published in MotorHome Magazine



The season for motorhome mouse-invasion is here. I wanted to share what we found in our 2002 Fleetwood Fiesta a few years ago. After owning it for a few years with no mouse problems, in the fall of 2012 we had mice. I searched everywhere to find an entry location, even using a creeper with lights and mirrors to look underneath, but I couldn’t find anything. Then my wife observed that the mouse “evidence” was always in the passenger foot space. Taking a closer look, I could see that the chassis heater outlet led directly to the outside air inlet, under the hood, when the heater control was not in the “recirculate” position. The mice had a direct highway from outside to inside. I closed this off with steel screening and we have not seen mice since.

John Foede | Madison Lake, Minnesota


Good sleuthing job, John! Who would have thought of that route but a mouse? Thanks for writing; this could help a lot of folks out there.


Ford F-53 Rain Ingestion and Oil-gauge Tip
In 2000 we purchased a new Fleetwood Bounder 32WB on the Ford chassis with a V-10 engine. Over the years we have solved a variety of problems, except one vexing situation: When driving in the rain, the air intake brings water up the vertical air intake and into the filter. The filter is a truncated cone with a plastic hemisphere at the bottom. Thinking I could avoid the hemispherical cup from filling with water, I drilled a ¼-inch hole. Now the water drains out but the filter element still becomes completely saturated. When this happens, the engine will intermittently cough. Fearing damage, such as hydraulic lock, I will have to change the filter (usually in the rain) and can only drive a few miles farther before a repeat. I am stymied as to what can be done. Do you have any ideas?

Also, here is a tip for Ford owners: The oil-pressure gauge is not a gauge. It is an idiot light in disguise. I lost an engine due to low oil pressure after a check-valve spring collapsed in the oil pump. There was enough pressure to show normal, but the gauge would pulse at idle. RV owners who have this situation should do as I did: Install an aftermarket oil-pressure gauge. All it takes are appropriate fittings to be installed at the base where the oil filter is installed. A tube is routed into the passenger compartment and attached to the gauge. The gauge-mounting bracket can be attached to the lower lip of the instrument panel. You will then have a functioning idiot gauge, and a real gauge.

Gary Blackburn | Palo Alto, California


Thanks for the tip on the oil-pressure indicators. This is also true on many Ford vans and pickups of the era.

Have a tech question?Over the years Ford has had several different fixes for the water-ingestion problem. Ford published technical service bulletin (TSB) 02-9-9 and issued a part No. YC3Z-9K635-AA for a shield kit. However, many owners reported that the earlier “fixes” didn’t solve the problem; they still drew air down low, where water got sucked in. I suggest that you simply modify your engine’s air intake so that you can slip a clothes-dryer-vent hose over the stock air pick-up and route it so that it’s above the grille opening. Hold it in place with large cable ties and hose clamps. Route it so there’s a low spot where water can collect, and add drain holes on the bottom.


Genset Quits
The Onan Microquiet 4000 genset in my 2008 Fleetwood Class C will typically start and run fine for about 15 minutes, but then will surge for a few seconds and shut off. After that it won’t restart until some time has passed. I took it to an Onan service center and they said they couldn’t fix a problem that doesn’t exist – they ran it twice, for an hour each time, with no problems. I was told to make sure to prime it for about 30 seconds, and to run it often and long. When I got home, it did the same thing to me.

My research leads me to hypothesize that it has an overheating issue, but it didn’t overheat at the service center. I have run it several times under no load, under load with the A/C fan only and with the A/C full auto, all with the same result, sometimes longer and sometimes shorter, but it always ends up shutting down on its own. I’ve put in a new fuel filter, the air filter is clean and services are up to date.

Scott David | Saugus, California


Don’t you hate that when you take something in for a problem and it doesn’t malfunction when you need it to? I think you are very likely correct in your guess about overheating. You live in an area where it gets very hot in summer, and that’s probably contributing to the problem. These gensets have an automatic shutdown which will stop the engine if excessively high temperatures are detected, and also if a low oil level is detected. Both rely on sensors, which of course can go bad completely or just out of range.

Always start by checking the oil level. Then, inspect for anything that might cause a restriction of cooling airflow, such as dirt and crud, trash, critter nests, etc. Make sure there’s enough gas in the tank.

If everything looks good, I suggest you have the shop replace the temperature sensor, just in case it has started to fail. Ask the mechanic to look the genset over for any other possible causes of the problem while it’s there. In the future, when testing it, do so in the hot sun with the air-conditioner compressor cycled on to create a significant load. The shop may have tested it on a cool day, parked in the shade, and/or without much load.


Ken FreundRV DIYRV Tech SavvyTech topics

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