Good Sam RV Travel Guide & Campground Directory

Mark...My Words

RV Care & Maintenance Tips

By Mark Nemeth

Hi, all!
This month: GPS, batteries, tires, generators, and more! I hope you are enjoying your summer vacation somewhere in an RV! Have fun, and keep those questions coming!

Continued from newsletter…

Hi, Mark:I've been trying to locate a GPS truck routing software for motorhomes. Preferably, a software that will route a motorhome owner through city and other streets like the trucking industry has. Driving a 45–ft. motorhome is just like driving a tractor trailer. I have a Garmin Nuvi gps system. Any ideas? Thanks, Keith

Hi, Keith:
Like most GPS manufacturers, Garmin makes a version specifically for truck drivers. Theirs is the nüvi 465T. TomTom makes the GO 7000 TRUCK. You can usually find a good selection of trucker's GPS units at larger truck stops. Based on some research, it appears that the map data for these trucker's units is not compatible with the standard car units. If you want to use the trucking maps with low clearance and truck route info, it appears that you must purchase the trucker's version of the GPS hardware device. Now, it may be possible to hack the car GPS hardware or to manually cram the truck map in there somehow, but for most folks, if you want the truck version, you'll have to cough up the bucks for a separate unit. A cheaper option is to purchase some printed truck guides, also available at most truck stops, and program in your route accordingly, using VIAs and avoids.

Hi, Mark:
This is Tom and Gail Winter. We were parked next to you at Quartzsite at Dennis and Carol's house party. Anyway, we have a 2005 Bounder with gas engine, and we tow a Honda CRV. After a 7–hour drive to Alpine, TX, we arrived at our campsite, and the car would not start because of a dead battery. This also happened last year. We have had to use our small charger to get it going again. We had the car battery and related systems checked twice for this problem. We also had them check the Bounder batteries. All report as okay. Also, before starting out each towing day, we check the connections to be sure the signal blinkers and brake lights are working properly. Question: What can we ask about at the RV repair place when we get home in October? Do you have any ideas for us on this? It is frustrating to say the least. Thanks for any help and direction you can give us. Tom and Gail

Hi, Tom and Gail:
I've heard about a few similar incidents, both with the CRV and other vehicles. Most vehicles with locking steering wheels require you to leave the key in and turn it to the "unlock" or "accessory" position. If you accidentally leave the key in the "on" position rather than "accessory" while towing, that will usually kill your battery in a few hours. If your vehicle is one that requires the key to be in the "accessory" position, be sure to turn off fans, the radio, and anything else that is energized when the key is in that position. If you continue to have problems, you might consider running a 12–gauge charge wire from the motorhome to the toad. That way, the motorhome engine alternator will provide some current to charge the toad battery while you drive. It is simple to implement. Just run a wire from the positive post of the motorhome battery, through a 20A fuse or circuit breaker, back to the motorhome's receptacle for the umbilical cord (where you hook up the lights for the toad). Make a similar connection between the toad's battery and the receptacle on the toad front bumper, using another 20A fuse or circuit breaker to protect it. Note: You may need at least a 6–pin connector and umbilical cord for this since you are adding an additional wire between the car and the coach. It doesn't take much current to keep the toad's battery happy, so it won't be a strain on the motorhome's charging system.

Over the years, I have been told that the normal fluid level in wet–cell batteries is the bottom of the fill tube. Actually, there is a slot in the bottom of the fill tubes so that the fluid level can be more easily seen. For the last 3 sets of golf cart batteries from Interstate it was found that the fluid level of new, off–the–shelf batteries was considerably below this level. In fact, at least one pint of water was required to bring the fluid level up to the bottom of the fill tubes in each battery. It seems that the batteries were never completely filled before shipping. If water is added to bring the fluid level up to the bottom of each fill tube, won't the specific gravity of the original acid be diluted? If others like me think that the proper fluid level is the bottom of the fill tubes and add water to new batteries, will these batteries live up to their full performance? What is your take on the proper fluid level in wet–cell golf cart batteries? Duane

Hi, Duane:
I have always filled mine until the electrolyte just touches the slot or ring at the bottom of the filler tube. The battery maintenance information on Interstate Battery's own website backs this up:

"Ideally, the water level should be no higher than just below or to the bottom of the tubes (in a 12–volt battery there are 6 tubes) that go down into the battery. To avoid damage to the battery, make sure the fluid level never drops below the tops of the lead plates in each of the cells."

I understand your question and can see some reason for concern, but I suspect that you will find the specific gravity of the cells is fine. While it's not impossible that the batteries where incorrectly filled, I suspect that it is more likely that they were filled to a lower level with a stronger acid solution for shipping, with the intention that, when the batteries were topped up by the purchaser, the water–to–acid ratio would be correct. The best way to find out for sure would be to perform an experiment! First, go ahead and fill the battery cells with distilled water to the proper level, based on the slot or ring at the bottom of the filler tube. Then, put the battery (or pairs of 6V golf cart batteries) on a standard 10A automotive battery charger overnight. Remove the charger and let the batteries rest with no load attached for at least 6 hours. Now, remove the cell caps and, using a temperature compensating hydrometer (which can be purchased for under $10 at an auto parts store), check the specific gravity of each cell. A fully charged battery should read 1.265 or more. If your hydrometer reads the cell as fully charged, then there's no problem with the dilution ratio of acid to water. If the reading is too low (below 1.265), then I suspect that the batteries were incorrectly filled at the factory and should probably be exchanged. If you decide to do the experiment, please let us know the results!

Hi, Mark:
I just bought a new set of tires for our RV. I went from load range C to load range D. I probably did not need the Ds, but I wanted to upgrade. My question is, since the new tires' max inflation pressure is 65psi, will it hurt the tires if we run at a lower psi? The old tires maxed at 50psi. I would appreciate your opinion. Thank you very much. Wilkrich

Hi, Wilkrich:
It's not as simple a question as you might think. While going up to a higher load range on tires seems like a smart thing to do, it can actually cause problems. As you have discovered, the higher load–rated tire specifies a higher max inflation pressure. What most folks don't realize is that the rim or wheel also has a max safe inflation pressure. For most steel wheels, the max pressure is stamped on the inside of the wheel. If you decide to go to a higher load–range tire and inflate it to a higher pressure, you must be careful not to exceed the rim's pressure rating! All tires should be inflated to a correct operating pressure based on the load they are actually carrying. Most manufacturers provide load/inflation charts for their products, but you have to know how much weight the tire is carrying in order to make an informed decision. You really need to get your rig weighed, as we are just guessing when we don't know the actual weight. For now, until you can determine what the correct pressure should be, you can try this: If you ran the old C–rated tires at 50 PSI and the tread wore normally and the tires performed well, you can probably get by with the same inflation pressure on the new tires or maybe just a few pounds more. If the weight of the rig makes a higher inflation pressure desirable, be sure to check the wheel ratings before you raise the pressure.

Hello, Mark:
My husband and I enjoy your column and always learn something new. Thanks very much. My question has to do with hot weather travel. Specifically, which is more efficient: running the generator and coach AC while underway or using the engine AC? We have a 2008 Winnebago Voyage (32 ft) with a Ford Vortec V–10 engine. I look forward to your advice. Liz

Hi, Liz:
Since modern automotive air conditioning compressors are very efficient, I think there's no doubt that running the dash air will consume less fuel than running the generator and a roof air. However, it becomes a matter of comfort and necessity when the temperatures get really high. On a warm day, the dash air will probably keep you comfortable, but on a hot day it will not be able to keep the coach cool. At that point, most folks light off the generator and turn on the roof air to keep the inside of the coach tolerable. You can expect a gasoline generator operating a single 13.5 KBTU roof air to consume around a gallon per hour, on average. Be aware that this will decrease your driving range slightly. Also be aware that most generators that draw fuel from the motorhome's fuel tank are set up with a higher fuel pickup height than the engine fuel pump. Most generators will starve for fuel and shut down when the main fuel tank drops below about ¼ full. This is done on purpose so that running your generator for an extended period in a campground will not leave you with a totally empty fuel tank on the motorhome. Be sure to check the generator oil daily, or after every 8 hours of operation when you are using it on the road.

I have a 2009 Challenger fifth–wheel. I am considering purchasing a generator for some boondocking. It has a 15,000–BTU air conditioner. Most of the literature I see on generators lists them as being able to power an RV 13,500 BTU a/c. Can you direct me to a site that might do some good reviews of this topic and also one that might have some good consumer reviews of different brands and models? I don't want to purchase something too cheap that I will regret and have problems with, but I don't want spend money on premium line equipment if good equipment will work. This is something that we would only use 2–3 times per year.
Thanks much, Casey

Hi, Casey:
It's good to ask the questions now before you go generator shopping! Most 15K–BTU roof airs draw around 2000–2300 watts while operating but require a large surge of current briefly when starting the compressor. Most 3000–watt generators are really not capable of operating a 15K–BTU unit in the real world, as they would require all other electrical loads be shut off in order to run the roof air. If you are at higher altitudes, or on a really hot, dry day, they may not be able to restart the compressor reliably when the roof air cycles. To be really safe, you need to look at a generator that produces at least 4000 watts. Some folks buy a pair of Honda or Yamaha 2000W inverter generators and use a parallel cable to combine their outputs. This is a good solution, because when you aren't running the roof air, you can get by happily on a single generator. You only pair them up when you need more power. I suggest that you avoid cheap contractor–style generators, as they are excessively noisy and relatively short–lived when compared to RV generators. You should do some searches on popular RV forums for topics related to 15K–BTU air conditioners and generators. This gets discussed a lot! Here are a few generator sales sites that have some buyer's guide information: also has a buyer's guide, but the URL is about a million characters long. Go to their site and look under Home > Outdoor Info > Field Guides > Camping/Hiking: Gear > Portable Generators Buyer's Guide.

Mark NemethMark Nemeth has been involved with all things RV for more than ten years, including almost 5 years on the road as a fulltimer. Nowadays, Mark is parked for a while and works on staff for the Escapees RV club as technical advisor, consumer affairs director, and instructor in the Escapees RVer's Boot Camp program.

Founded in 1978, the Escapees RV Club provides a total support network for Rvers that includes a wide variety of opportunities for fun, adventure, and education. CHAPTERS There are 51 chapters across the U.S., Canada, and Mexico that offer local luncheons and rallies within 150 miles of home. Everyone is welcome to attend. HOPs Theme–related outings and adventures held across the country. ESCAPADES Five–day events, Escapades offer over 60 seminars and workshops to educate, entertain, and enhance the fun and use of RVs. PARKS Our RV park system offers short–term, long–term, and home–base parking options. MAIL SERVICE The best mail–forwarding service in the country. Members can personalize their mail delivery receiving only the mail they want when they want. PLUS MUCH MORE! A complete listing of all Escapees events, and a comprehensive list of member benefits are found at

Escapees RV ClubSome content previously printed in Escapees magazine, published by the Escapees RV Club. All material provided by Mark Nemeth, Escapees Magazine Technical Advisor and Boot Camp Instructor. For more information about the Escapees RV Club, please visit or call 888–757–2582.

Woodalls subscribers can save $10 on a new Escapees membership! For more information, visit the Escapees website.

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