RV Tech Savvy: Power for a CPAP Machine

CPAP Machines

Question iconAs a follow-up to September’s “Using CPAP Machines” letter, I also have a need for a CPAP machine. Partly for me and mostly for my better half (no more snoring, that is). We have a 2017 Winnebago SunStar LX 35F, and when on battery power, the electrical receptacle by the nightstand is not converted to 120 volts AC. I have to plug in an extension cord into the converted receptacle by the TV. The issue here is that my wife has tripped over it at night. She has at times pulled the CPAP machine off the nightstand and wakes me up with the air tube wrapped around my neck. Is there a way that I can make the receptacle on the nightstand connect to the inverter? I’m sure there are others who have the same question.

Michael Muir | Twinsburg, Ohio

Answer iconTaking a look at the wiring schematic for this motorhome, it appears that your nightstand is in the slideout on a completely different circuit. In order to have the nightstand receptacle be serviced by the inverter, you’ll have to rewire at the power distribution panel. I suggest that you take the motorhome to your nearest Winnebago dealer, preferably the one you bought it from, explain your situation, and see what it can do. Wiring diagrams are available on the Winnebago website, at http://winnebagoind.com/resources/manuals.

Leaky Light

Question iconWe own a 2003 Winnebago Adventurer 35U. Last spring, we found water dripping on the dash. After a little exploring, I discovered a broken clearance lamp that was not noticeable from the ground. I figure it must have been struck by a bird on the last trip out.

Answer iconThe fix should have been simple: two screws, a $10 lamp and a gasket. After taking the lamp to three dealers in the Tulsa, Oklahoma, area I’m not having any luck. Camping World called Winnebago and found that the vendor is out of business. No problem, Colaw salvage is only 125 miles from Tulsa. Colaw was willing to help and asked me to send pictures. I sent some photos with a tape measure showing dimensions, but they couldn’t help. Salvage yards that I found on the Internet also couldn’t help. They all want to sell front clips, not a $10 lamp. These five front lamps are recessed and can only be replaced with the exact lamp. I’m told it is illegal to drive with duct tape over the recess. I would appreciate any help or direction you can give; we have been shut down this year for want of a $10 lamp.

Joe and Gwen Russell | Sapulpa, Oklahoma

It can be frustrating when something like this occurs. But don’t give up RVing because of it. Very few police will stop you for one clearance light being out, and most of them would accept your explanation that you are trying to find one because they are discontinued. In the worst case, you might get a fix-it ticket or small fine. The lights don’t have to match, they only have to be working and DOT-approved. I suggest that you go to the nearest auto parts store and find the closest light that will fit, and install it. Then fill the space around it with sealant. During your travels, stop at RV salvage yards (you can find them with a Google search) and inquire if they have something. Good luck.

Surround Sound … Doesn’t!

Question iconWe have a 2006 Class B Gulf Stream Vista Cruiser with a 2.7-liter turbodiesel. I bought it a year ago and have been unable to get the surround sound speakers to work. On the radio knobs, I do see the surround sound speakers, and TV/video, etc., but haven’t had any luck. I’ve checked the fuses, etc. Before I take it to a shop, I just wondered if anyone has had the same type of problem.

Jack Adam | Bay City, Michigan

Answer iconYou didn’t mention if you have any sound at all, or what brands of components you have currently installed. When the motorhome was new, it came with a Flip Down TV/DVD/CD/FM entertainment unit with four speakers. The issue is most likely with this unit, unless the system has been replaced since it was new. If you don’t have the original owner’s packet or the manual for the TV, I recommend looking up the make and model on the Internet and searching for the manual where you can check the troubleshooting information.

Make sure the source of the sound is OK (i.e., the TV). Next trace the wiring and confirm there are no speaker switches in the circuit somewhere, which are often located in a cabinet. It’s possible the TV and dash stereo share the same speakers. Then, if that doesn’t work, check all the wiring connections for the TV and each speaker.

If I had to hazard a guess, I would say there’s either a speaker switch somewhere (or a relay of some kind) or there’s a problem with the output of the TV.

Refrigerator Makes Battery Go Dead – Tip

Question iconIn your answer to Mike Morgan (“Refrigerator Makes Battery Go Dead”) in the September issue about his refrigerator drawing too much 12-volt DC power, you didn’t mention the possibility of a climate control heater on his refrigerator being the problem.

Have a tech question?We don’t know what brand of refrigerator he has, but my Dometic has a climate control heater that draws 12-volt DC power and the company recommends turning it to off when a charging source is not available.

Doug Wolf | Pueblo, Colorado

Answer iconThanks for reminding me of this feature, Doug. It uses a lot of 12-volt (battery power) to heat up the refrigerator wall surface so that it doesn’t allow moisture in the air to condense and drip down. Folks with this feature should turn this function off when camping without hookups.

Stationary Use

Question iconI have a 2015 Fleetwood Bounder gas motorhome. This winter I will be parked on gravel in an RV resort for about six months without moving. Usually I move around. Is there anything I should do while parked to maintain the motorhome?

Karen Manning | Boise, Idaho

Answer iconThere are a number of things to do. I suggest that you add fuel stabilizer, such as STA-BIL, before parking. Also, exercise the generator according to its owner’s manual instructions. Make sure both the engine and house batteries are kept properly charged and full, using distilled water as needed. In addition, be sure tire pressure is kept at specified levels. If you’re staying in cold weather, winterize the motorhome’s plumbing system for local conditions.

Squeal on Startup

Question iconWhy does my 1993 Fleetwood Bounder squeal loudly every time I start the engine? The squeal lasts for up to four minutes. What can cause this?

Mike “Doc” Holliday | Via email

Answer iconThis problem is almost always caused by a slipping drivebelt on the front of the engine. When you first start the engine, the alternator goes to a high charge mode to try to return the power to the battery that was expended during cranking. This takes several minutes, typically. Hence there is more load on the belt at this time. As the belts get old they stretch slightly and harden, which can cause them to slip. You should be able to confirm this by having an assistant start the engine while you stand in front with the hood open, listening for the direction of the noise. Given the age of your motorhome, and the fact that it has been slipping so much, I suggest that you replace the belt.



  1. Wife and I both are on CPAP. I installed two cigarette lighter adapters next to each side of the bed and tied into the 12 volt light system. We bought 12 volt power cords for our machines and have been happy campers ever since.

  2. Many CPAP machines actually have an inline transformer to convert 110 volt to 12 volt DC. It is so much more efficient to run directly from the battery rather than through the inverter then back to 12 volt. It just takes some wire and connectors; our works great. Some manufacturers actually sell hookups that plug into cigarette lighters for CPAP.

  3. I have a 2018 Travato, by Winnebago, and notice that when we are remote camping that it does not have a battery connect to a 120 outlet that can be used without the generator running. I just need something simple to use a Hot Shot to make hot water for tea.
    Is there any way to connect one of the existing outlets or even add one?

  4. Some CPAP have a converter in the power cord. Mine has one. I purchased a 12 volt cord that plugs into the 12 volt power outlet. if you use the humidifier that may be equipped with your CPAP, it suggested to turn off the humidifier as it will draw the battery down faster. if you are on a one night without 120 volt hookup, it would be ok to use the CPAP humidifier.

    I purchased my 20 foot 12 volt extension cord at Camping World and the 12 volt plugin [6 foot long] for my CPAP at a battery shop in east Portland Oregon. My 12 volt plug is at the opposite side at the end of my bed which caused me to buy the 12 volt extension cord.

  5. I forgot to mention I used wire clamps to attach to the lower edge going around the bed then under a small rug so we don’t trip or catch our feet on the cord. when we have hookups I pull the 12 volt cord and pace under the bed overhang.

  6. As far as the re-wiring for you CPAP machine…..I bought a new Holiday Rambler with the bed on the slide…..I have no idea what they did to make the receptacles inverted but it took them about 15 mins to do mine….guess they had a guy that knew what they were doing with wiring, be cause everything else they tried to do was junk….but I don’t snore at night which saves the wife a sleepless night


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