House Calls with the RV Doctor
By Gary Bunzer
Dear RV Doctor:
I have a 1990 Fleetwood Southwind with two air-conditioning units. They are on a front/rear switch so you can use only one unit at a time. The rear one works great, but if you turn the switch to front, nothing happens. They both worked last week and I haven’t done anything except take it to have the oil changed and an alternator replaced. Other than the main panel, is there another set of breakers or fuses on the unit? With the generator on and the rear air going, if I turn off the A/C breaker, nothing happens; in other words, the rear A/C unit keeps going. The front unit will not even turn on now, so I am really puzzled. Any ideas?
RV Doctor: I know it may appear slightly confusing, Phillip, but there is a logical explanation. Your Southwind was wired for two installed roof air conditioners, but because the shore power cord is rated for only 30 amps, you are able to run only one roof A/C at a time. Remember, each air conditioner must be on its own 20-amp circuit. That “either/or” (front/rear) switch lets you choose which air conditioner to run while plugged into shore power. Running both units off the shore line, as equipped from the factory, is mathematically and electrically not possible, hence the need for the “either/or” switch.
The generator adds another factor into the mix. It is rated to power both roof air conditioners at the same time … it has enough output capacity. Typically, the rear air conditioner is hard-wired directly to the generator output. On the side of the control box on the generator, you’ll find two push-button circuit breakers; one is wired directly to the rear roof A/C (that’s why the rear unit runs with the generator operating), and the other breaker is wired to the coach distribution panelboard, which protects all the 120-volt circuits in the coach, including that front A/C.
Chances are, given your symptoms, the front air conditioner breaker in the panelboard distribution box is faulty, the “either/or” switch is faulty, or there could be a problem with the wiring to the front roof A/C. There is also an outside chance a problem in the front air conditioner could exist as well.
A few simple continuity measurements with a volt-ohmmeter should clear up the mystery. If there is continuity through the “either/or” switch from the panelboard breaker to the front A/C, then the problem lies in the air conditioner itself. If there is a break in the continuity anywhere between the breaker and air conditioner, it would implicate either the circuit breaker itself, the “either/or” switch, or a wiring connection somewhere in between. A competent RV tech should find where the problem lies in about an hour’s time. The repair, however, may take longer depending on the actual cause of the symptoms.
Dear RV Doctor:
I have a 1999 type A motorhome. The bottom step at the side entry door always gets wet, and I mean soaked, every time it rains. The water seems to accumulate at the bottom of the door on the outside of the seal, and then fill up and over the lip of the threshold. I’ve checked the seal on the door, and it seems to be okay. How can I stop this?
RV Doctor: Mike, in some cases it is possible to place small shims under the bottom of the door frame, creating a slight ramp downward and outward toward the exterior. Of course, this may also raise the bottom of the frame such that it will require an adjustment to the action of door closing. A careful inspection of the construction of the door frame from inside the coach will determine where best to place the shims. The shims should be aluminum so that any contact with moisture will not cause additional problems; I’ve used strategically placed aluminum washers in the past. And I would indeed double-check the integrity of that door seal. But I would wager it has more to do with the actual slope of the threshold itself.
Wood Or Is It Metal?
Dear RV Doctor:
Is the floor of the typical Tioga motorhome from the ’70s wooden or metal? Should I use linoleum, hardwood, or carpet to cover the subfloor? This is my first RV.
La Mesa, California
RV Doctor: Stephen, the flooring on your motorhome, as well as those on the majority of coaches built in the 1970s, should be plywood. There would be a covering of aluminum on the bottom, that portion exposed under the rig and on top of the frame rails. Your coach originally came with carpeting in the living area, along with possibly linoleum in the lavatory and galley areas. As long as the plywood underlayment is properly prepared and there is no water damage or dry rot, it is possible to refinish the floor with any of the materials you mention, or even tile in some cases.
Proper preparation includes making sure each section of plywood is flush at the joints and all the screws or staples are fully seated and well below the level of the top of each sheet of plywood. Common wood filler may be used to close cracks and fill holes. A final sanding to make the floor as even as possible is yet another step in the process. Finally, a clean sweep will have that old flooring ready for any type of top floor material you choose. Of course, if there is any evidence of water damage, that will have to be taken care of first.