Tech Talk: January 2010

Coach Tires

I am experiencing some abnormal wear on the front tires of my 2005 Fleetwood Bounder 38N. These are the original tires and have only 25,000 miles on them. I first noticed the wear approximately a year ago and had them inspected by a tire dealer. The wear is occurring primarily on the second rib in from the outside of the tire. It is a little more noticeable on the passenger side, although the driver’s side is showing the same wear. I was told this could be happening because the tires are underinflated. I had been running 90 psi, which is the pressure indicated on the label in the motorhome. The dealer told me to run 105 psi, which I have been doing, but the wear seems to be continuing.

From what I have read, this condition is referred to as “rivering.” After discovering the problem, I also had the front end alignment checked, and it was deemed okay with little correction needed. The rear tires are wearing fine. Any help, comments, or suggestions?

Marvin Ussery, F375490, Daphne, Alabama

River wear, also called erosion wear, is a condition in which the outer edge of the tire’s ribs will wear faster than the center. This is seen mostly in tires that are used predominantly for long-distance travel on highways where there is little tire scrubbing from turning. Tires used in high-scrub applications where regular turns are common typically will wear across the entire tire and not show river wear.

To limit this type of wear, a representative from Goodyear made two suggestions. First, ensure that the tires are properly inflated. To do that, you must have the motorhome weighed. Underinflated tire conditions can be caused by overloading them, even though the tire pressures may meet what the manufacturer recommends. Raising the pressures as you did will only degrade your motorhome’s ride comfort, not improve the wear if the vehicle is overloaded. Since the two front tires are wearing at different rates, you need to weigh each corner of the coach to determine whether a specific tire location is overloaded more than another.

The Goodyear rep’s second recommendation is to have the tires rotated. Once abnormal wear begins, the wear will continue unless the tires are rotated to a different location, which will change the wear characteristics.

I have a 2005 Fleetwood Revolution. The chassis batteries discharge after about five days, at which time I can’t get my engine started without jump starting it. The batteries are a year old. I also do not think the auxiliary start unit is working. What could be the problem?

Also, how do I check to see if the solar unit is working?

Bill Jones, F358207, Orange, California

The first step is to charge the batteries and have them load tested to determine whether one of the batteries is bad. If all of the batteries test okay, the next step is the tough job of Ohm testing all of the 12-volt lines connected to the batteries to determine the location of the current drain.

If the auto start system works off of the house batteries, bad batteries may be the problem. But if it works off the chassis battery, you may need to call the company that made the auto start. Are you sure the auto start is programmed properly? (See owners manual.)

To check the output of the solar panel, disconnect the wire leading to the controller and use a voltmeter to determine the voltage coming from the solar panel. Reconnect the wire to see whether that same voltage is measured from the output of the solar controller. If it is not, you have a bad controller.

Which Satellite Dish To Buy?

I have an old KVH in-motion satellite antenna and want to upgrade to HD reception. Every manufacturer says theirs is the best. KVH and King Controls have the domes, but we’ve had reception issues during rain and on cloudy days with the existing KVH system. I’m sure technology has changed in eight years, but where can I find a type of “Consumer Reports” study that compares the pros and cons of the most popular systems? We are DirecTV subscribers, and it seems the dome ones must do some satellite switching, while Winegard has its low-profile antenna that captures all five of DirecTV’s satellites and avoids any switching or extra “boxes” to buy. There’s no dome to protect the antenna, but it appears pretty beefy. Could you please point me in the right direction or advise me on your recommendation?

Steve Koltvet, F369428, Auburn, California

I’d love to tell you to run out and buy Model X and tell you that you won’t be disappointed, but we haven’t done any comparison-type testing that would allow us to make specific recommendations regarding satellite TV antennas. We can say that no matter what type of antenna you choose, you’re bound to run into reception issues during inclement weather. There’s nothing you can do when storms block the signal coming from the satellite to your antenna.

However, you may find some help in choosing the antenna that is best for you by checking out the “Satellite TV Antenna Roundup” article that appeared in the October 2008 issue of Family Motor Coaching (page 56).

I own a 2006 Newmar 43-foot Mountain Aire that has two roof-mounted Dometic Penguin low-profile air conditioners that cool the motorhome via a ducted ceiling system. I need to replace the rear unit, and I would like to do it myself since I’m in an area where there is no RV service. It seems to me that it would be fairly straightforward “” take the old one out, put the new one in, and reconnect the electrical wiring. I am mechanically inclined and feel confident of my ability to do this. However, since I have never done it before, are there other considerations that would require the services of an air-conditioner technician?

Dick Slosar, F273176, Key Largo, Florida

Newmar does things a little bit differently when it comes to installing the roof air conditioners. Yes, you can do the replacement and it is very straightforward. However, Newmar attaches the air conditioner base pan to the framing of the RV roof from the topside, since they do not have a conventional 14-inch-by-14-inch ceiling return air vent.

Make sure to order the correct roof air conditioner for the style of thermostat you have (Comfort Control Center or Analog) and with the control board in the roof unit (as opposed to those that mount in the return air cavity). The air conditioner will come with a new roof gasket, but you also should replace the special duct air seal to ensure a leakproof fit to the ductwork. This seal may be available only through Newmar.

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