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RV Tech Savvy: Heat Distribution

Originally Published in MotorHome Magazine

Red letter Q

We own a 2014 Coachmen Encounter 36A motorhome. When I turn on the furnace, there is great heat in the back bedroom and the bathroom turns into a sauna, but I get nothing in the front vent. I can feel a very slight warmth out of the vent, but zero airflow. Is there a safe way to increase that frontal airflow? My issue doesn’t seem to be unique after talking to several other travelers last winter.

Bob Krafft | Alpena, Michigan

Turquoise letter AYou need to follow the heat ducting from the furnace to the last register at the front. It’s normal to have less airflow from the register at the far end from the furnace, but you should have something. It’s likely you will find that the ducting is crushed, closed off or otherwise blocking flow. It’s also possible that the heat ducting was poorly designed. Unlike home residential builders, some RV manufacturers, regardless of manufacturing experience or price point on the market, miss the mark when implementing ducting systems that will deliver the right volume of warm air to the right places. A certified technician should be able to diagnose and repair your motorhome’s system.

Freightliner Alarm Sounding

Red letter Q

We have a used 2007 Tiffin Phaeton 40QSH on a Freightliner chassis. When I start it up, an alarm goes off until the air pressure builds up, then shuts off. I assume this alarm is only connected to the air system and no other systems such as temperature, oil, etc. The alarm also sounds occasionally while we are driving. Many times, after we hit a bad patch of the road, it will go off, but may stop in a couple of minutes or even an hour or so. Other times it goes off when the road is smooth. When it does, all the gauges read correctly and the coach runs fine. On other trips, it never goes off.

I wonder if it’s a loose wire, but it’s probably more than that, possibly a faulty sensor. If it sounds and I shut off the coach for a minute or two, it doesn’t come on again when I start it up. The top air gauge is somewhat faulty. Once in a while, the needle seems to be loose, but most of the time it reads correctly and when the alarm goes off it doesn’t move.

I am planning to have the gauge replaced and the alarm looked at but I’m not sure if this is the cause. It’s hard for a mechanic to find out what is wrong if the alarm doesn’t sound while it is in the shop. Any ideas?

Ray Killen | Mountain Home, Arkansas

Turquoise letter AThis is a known Freightliner chassis problem. It’s likely faulty wiring on the back of the dash, but it may also be a gauge problem. Contact the call center at 800-385-4357 and a representative will ask you some questions to determine which fix is needed. Have the vehicle identification number (VIN) on hand when calling.

Tire Life

Red letter Q

Given that tires are so expensive, does covering them (with tire covers) affect the lifespan? It’s usually about six years when they time out. Our coach is stored most of the time and I go for a drive at least once a month.

Steve O’Brien | Redwood City, California

Turquoise letter AHow tires are used and stored definitely affects their condition. Tires that are left out in the sun deteriorate faster than those stored indoors or in the shade. I’ve seen tires that were stored lying on the ground in the desert that were totally cracked and dried out on the side exposed to the sun, while the side facing down showed no weathering. I recommend tire covers when parked for long periods of time outdoors, and if you want to go one step further, treat the sidewalls with a coating of silicone-free protectant before adding the covers. Tires still age, though, and they should be inspected by a tire expert once they reach about six years of age.

See Motorhome Tire Basics for more info

Ford F-53 Steering

Red letter Q

This is in regard to the Ford F-53 steering article, “Straight as an Arrow”). The off-center steering wheel on the Ford F-53 chassis, in my opinion, is a safety issue. My eyes are straight ahead while driving, but when I glance at the instrument panel I see the steering wheel center bar is crooked, and it causes me to move the steering wheel to get it straight, and off the road or into the other lane we go. Ford has known about this for years and has done nothing to correct the 6-degree spline design. Why must I pay over $500 to correct Ford’s design flaw? I wonder why the National Highway Traffic Safety Administration (NHTSA) has not forced Ford to do a recall, repair and redesign? This is a design flaw and Ford should be held accountable to fix it.

Vince Povio | Pompano Beach, Florida

Turquoise letter AAlthough I didn’t write the article you mention, I do feel your pain. Many vehicles have a way to adjust for this, either with an adjustable drag link or individually adjustable tie rod ends. While it is annoying, I don’t think it meets the criteria of dangerous or life-threatening, which might trigger an NHTSA investigation and perhaps a safety recall. You might consider a formal complaint to Ford, the NHTSA or a letter to our Hot Line column.

Boiling Batteries

Red letter Q

There is a battery boil-over problem on my 1997 Monaco. When I plug in to 120-volt AC power, my coach batteries boil over. Is this an amperage problem from the 120-volt AC circuit, or is my Xantrex Freedom 25 power converter going bad? Are they repairable? I’ve read that these chargers are no longer available.

Have a tech question?Alex Razkowic | via email

Turquoise letter AI suggest you first measure the voltage coming into the coach to verify it’s at or near 120 volts AC. Then measure the output voltage from the charger at the battery terminals. You can refer to the owner’s manual, which is available online. Float voltage should be about 13.1 volts in warm weather and 13.5 volts in cool weather. Electrolyte starts to “boil” when in a float stage above around 13.8 volts. If you are unsure how to test it, consult a qualified RV center. These units are discontinued, so it might be time to update and upgrade.


Red letter Q

I am looking to buy a new vehicle to tow behind my motorhome. I have a tow dolly. Does MotorHome have a list of vehicles, or are all front-wheel drive vehicles towable?

Clifford Ver Hey | via email

Turquoise letter AMotorHome has published annual dinghy towing guides for many years. These guides list all vehicles approved by their manufacturers for flat towing. They are available for free. Although a considerable number of front-wheel drive models with manual transmissions are dinghy towable, no assumptions should be made. Having a tow dolly allows you to tow many front-wheel-drive models that aren’t approved for dinghy towing. Make sure to review the owner’s manual and verify that the vehicle can be towed on a dolly before purchasing.


Ken FreundMotorhome 101RV DIYRV TechRV Tech Savvy

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