RV Air Conditioner Inop On Generator Power

I have just borrowed a 29-foot motorhome. I'm leaving shortly to go to a NASCAR race. The air conditioner works wonderful when using the extension cord and running off my electrical power but it doesn't work at all when the generator is on. Is there a switch I must throw to get it to convert from extension cord to generator? William J., (Ashville, NC)

William, typically, to get the AC electricity produced by an on-board generator to power the RV, it requires one of two methods. The first is automatic; an automatic transfer switch, (usually with a time delay), senses the presence of voltage produced by the generator and automatically energizes the panelboard distribution panel in the RV and prohibits further input from the shoreline cord. Motorhomes are wired so that two different sources of 120-volt AC electricity cannot feed the coach at the same time. The automatic transfer switch provides that methodology for both the hot and the neutral power conductors. 

The second process of getting generator power to the rest of the rig is by manually plugging the shoreline into a dedicated receptacle wired directly to the output of the generator. In other words, to get AC power to the RV you must plug the shoreline cord somewhere; either into an electrical source such as a campground pedestal, or into the generator receptacle. It’s usually located inside the same compartment as the shoreline cord. Pull the shoreline cord all the way out and look inside that compartment with a flashlight. I'm guessing you’ll see a 4-inch square box with a 30-amp female receptacle. Be sure all loads are turned off, then plug the shoreline cord into that receptacle and start the generator. If all the breakers are set properly, you should get power to the coach. Of course, you may have a problem with the transfer switch itself if your coach is so equipped. But that’s a whole ‘nuther issue! 

And depending on how old that motorhome is, there is a third method of obtaining generator power that mandates the user flip a set of circuit breakers. The older GMC motorhome had such a set-up at one time. The user had to manually flip the breakers from shore power to generator power.

Also keep in mind all RV generators are protected by an integral set of circuit breakers located on the generator itself. It is possible everything in the motorhome is fine, but the breakers on the generator itself may be tripped. Look on the generator and be sure its integral breakers are in the on position.

Foul Odor From RV Batteries

On a recent camping trip, we were connected to 30-amp shore power. During the night, our CO alarm went off. Since there was no stove or furnace operating, I felt the alarm was defective. I did notice the coach battery compartment was warm to touch. Later when entering the coach from outside, I noticed a foul odor that I couldn't identify. We drove the motorhome back to Cincinnati and hooked it up to shore power (30-amp). This morning I went to the RV and the CO detectors, (2 of them), were going off. I opened the battery compartment and found the batteries and cables very warm and the same foul odor. Is it possible that the batteries are producing carbon monoxide poison? Fred N., (Cincinnati, OH)

Fred, the charging and discharging of the batteries will not produce carbon monoxide, but unless charged properly they will off-gas a foul odor consisting of a combination of hydrogen vapors and sulfuric acid. Rapid charging or rapid discharging of the batteries will also produce an abnormal amount of heat as well; as you’ve noticed. 

I’m not sure what brand of CO detectors you have, but it may be possible they are sensitive to the boiling of the electrolyte that is probably taking place at the batteries. It's also possible the detector has become contaminated or is at the end of its effective lifespan. Check the "Replace By" date tag or label on the back of the detector or in the literature provided. Most detectors will need replacing at about the seven year mark, but check your date code to verify.



Without having the benefit of running some tests and taking some measurements, I’d hazard a guess that the AC-DC converter is overcharging the battery bank every time you are plugged into shore power. Be sure to keep a close eye on the electrolyte level in each battery in that bank until you rectify the problem. It can literally boil the water right out of the electrolyte, produce heat and off-gas the hydrogen and sulfuric acid. This is the odor, I believe, you are smelling. 

In my opinion, many stock charging converters are not sophisticated enough or engineered with circuitry designed for the complete and proper charging sequences necessary for optimal charging of commercial grade deep cycle batteries. Many have a propensity to overcharge the battery bank. I’ve always suggested investing in a dedicated three-step battery charger and allowing the converter to convert and have the battery charger, charge. Multi-stage, processor-controlled chargers can be user-set to accommodate any type of battery so it knows how to charge, when to charge, and at what current and voltage so that overcharging does not happen. 

But be sure to verify the integrity of the CO detectors! Never compromise the safety factor! You'll want to update your detectors if they need replacing. They sounded off for some reason! 

Curling RV Decals

I own a 2004 Flagstaff fifth-wheel which, as far I know, has always been outside with no protective covering. The decals on all sides have started to curl up during the last couple of years. Is there any way to restore (re-glue) or replace the decals? I have had some people tell to take them off and go "au natural." I'm not sure I want to do that but will if need be. Richard W., (Boniare, GA)

Richard, a sad fact to realize is that constant exposure to the elements and the changes of seasons, RV exteriors take a lot of abuse. Even when properly cared for, UV bombardment and ozone contamination simply happens. At some point, all decal-type graphics on RVs will have to be replaced. You are apparently at that point now. The glue backing has simply lost its inherent sticking ability and there is virtually nothing that can be done except look for some replacement striping. Perhaps your dealer can order something of the original size and color for you. Extended life can be realized for decals and other graphics by always using a full-coach cover when the RV is not in use. And by cleaning and protecting the finish regularly, two or three times a year. More often if you live in areas of high ultra-violet radiation or ozone producing zones. A more expensive alternative is to opt for all-paint graphics. 

Here's another related question that might also provide some insight.

RV Absorption Refrigerator Relativity

We recently purchased a used 2007 motorhome and haven't actually camped in it yet but have done some local driving to get used to it. We’ve been reading about the leveling for the refrigerator and understand the necessity. We have a two-door unit, (top freezer and bottom refrigerator). My husband is concerned about leveling while driving such as on hills and mountains. Should we be? Rosemary P., (Tucson, AZ)

Rosemary, leveling is important during any operational mode (12-volts DC, 120-volts AC or propane), but only while the coach is stationary. When physically moving down the road, there is enough jostling and movement to keep the liquids and vapors safely flowing through the sealed system of the absorption refrigerator. It is only crucial when the vehicle is not in motion. And with today’s cooling core design, it’s not as crucial as it used to be. Today, as long as the motorhome is “relatively” level, the cooling unit will be safe. 

I once asked a refrigerator manufacturer what “relatively” level really meant and the bottom line is this; if the eggs don’t roll off the countertop or if the blood doesn’t rush to your head while sleeping, the refrigerator will be fine. Still, while standing still, try to get it as level as possible. It’s just not worth the risk in my opinion. 

Operating the refrigerator off level creates an inordinate amount of heat at the rear of the unit, especially in the boiler area. Coupled with improper ventilation this extra heat can escalate very quickly into potential costly troubles. When overheating occurs over a period of time, the sodium chromate inside the pipes begins to crystallize (sodium chromate is used to protect the insides of the tubing from the corrosiveness of the ammonia). Typically the blockage will occur in the percolator tube, one of the smallest of the internal tubes inside the cooling core. The percolator tube inside the boiler section can become impassable because of the blockage (see photo). When this happens, the cooling unit is blocked and cannot be repaired. It must be replaced with a new or reconditioned unit. 

Leveling is one of the two most important factors to consider when using the RV absorption refrigerator. As mentioned, the other is ventilation. There must be a continuous, chimney-like ventilation space behind the refrigerator all the way up and through the roof. But tell your hubby, as long as he keeps moving he need not be concerned.

Multiple RV Water Pump Failures

We have a Forest River Class A motorhome and have had five failed water pumps made by ShurFlo for our fresh water system. Carol P., (Pattersonville, NY)

Carol, I’m not exactly sure what your question is, but it amazes me that you’ve gone through five water pumps! Has anyone been able to determine exactly what is causing the pumps to fail? And more importantly, which component(s) on the pump(s) are failing? 



ShurFlo has a very fine product line and stands behind their pumps. Personally, I’m a big fan of their pumps. Here's a short video highlighting the features of one of their newest pumps.  

Also, keep in mind, it’s difficult to simply wear out an RV pump, especially with the unique design of the ShurFlo pump head. Be sure you have a filter/strainer installed between the tank and the pump. A regularly cleaned strainer will keep particles of what I call “tank trash” from migrating from the tank to the pump, causing harm. And be sure there is plenty of ventilation around the pump motor. If the motor is component that is failing, it could be heat related, but they are equipped with an integral, automatically resettable overload protective device. I would love to learn the cause of those failures; as would ShurFlo!

Leaky Slideout

I’m a single woman and have a Fleetwood Bounder. When it rains and I bring the slideout in and I un-level the motorhome, water from on the top of the slideout comes pouring into the rig. My RV dealer says this is normal. It's quite a bit of water and others I know do not have this issue. Shouldn't there be a seal to stop the water from coming in? Linda F., (Centennial, CO)

 

Linda, indeed this is not a “normal” situation. It appears that dealer is either misinformed or disingenuous. There should be a wiper seal around the slide room opening that should remove most of the water as the room is retracted. In some cases, it may not remove absolutely all the moisture, but it certainly should wipe most of it away as the room retracts. Apparently, the room needs adjusting or the seals need to be replaced. Have a certified RV service technician inspect the centering and all the adjustment points on the slideout. In a worst-case scenario, an aftermarket topper awning can be installed that will protect the room’s top surface when extended. It will extend and retract with the room. It’s an advantageous add-on device since it will also keep the room cooler in the summer as well. But I’m not buying the “normal” claim of that dealer.

RV Inverter AC Ground Problem

We sure enjoyed your seminars at the FMCA Rally! We have a Magnum inverter in our Monaco. On shore power and generator power, all the receptacles check “good” using a three-light, plug-in tester. However on inverter power, the receptacles show an open ground on both circuits. I have checked connections in the inverter block and it is wired correctly plus all connections are tight. The same in the main breaker panel. I have owned this coach since new and have used the inverter only twice for short periods of time, so it may have come out of the factory like that. Since everything worked, I never gave it a thought to test the circuits. I was checking which circuits were inverter powered with the idea of installing a residential refrigerator at some point. Bill W., (Gilbert, AZ)

Bill, I’m not a huge fan of those plug-in testers. I, too, used one for many years until one of my electrical engineering buddies found some inconsistencies while comparing and using them. Now I always rely on a digital volt, ohm multimeter (VOM), for all electrical measurements just to be safe. But you state your circuits work fine and show the correct polarity using the generator or the shoreline, so chances are your plug-in analyzer is working. But to be sure you indeed have an open ground situation on the inverter output, it’s better to use a VOM while troubleshooting. There should be an integral ground connection from the main panelboard distribution box through the inverter and any sub-panels, and ultimately to chassis ground. Here’s a paragraph from the Magnum manual for your inverter:

Wiring the Inverter AC Ground 1.  Combine the ground (green) wire from the main panel’s ground buss bar and the ground (green) wire from the sub-panel’s ground buss bar (or the ground connection on the outlets, if using the output breaker versions). After these grounds are combined, use field wiring leads to connect them to the inverter’s AC GROUND (green) wire.

So be sure you can read continuity between the ground buss bar in the main panel and the ground terminal on the Magnum. The ground path should remain constant throughout the entire AC circuitry. The hot and neutral conductors will be switched through the automatic transfer switch, but the ground conductor should not be switched. It could be a ground wire came loose some where in the system between the inverter and the breaker box(es). But measuring with a VOM should determine if and where the open exists. Since an open ground circuit is potentially dangerous, it may behoove you to contact a certified RV technician to perform further testing and measuring just to be safe. 

RV Water Heater Blues

I was winterizing our ten-year-old coach and flushing out the water heater. Some scale, I know, is usual, but what came out were lots of blue flakes. I am assuming that this is the glass lining of the tank and that the heater is basically totaled and not usable. I'd be very pleased if you could confirm that for me. George N., (no city/state)

George, unfortunately, it is relatively easy to inadvertently scrape the inside of the tank if you insert a long wand or tube inside the drain plug as you flush out the inner tank. One way to determine if the flakes are actually pieces of glass or the chemical result of something else, is to put a few of them in a cup of vinegar and see if they dissolve. If they do, then it's probably some type of mineral deposit that reacted with the composition of the water in the tank. If they do not, they could be little pieces of the glass lining though I'm not 100% certain they would be blue in color. Assuming they are indeed glass slivers from the tank lining, the obvious safe action would be to replace the complete water heater (or at least the inner tank), and not take any chances of having them migrate further into the hot side of the fresh water system. But try the dissolving test first and let me know what you find out. It could simply be some type of mineral reaction between the anode and the water PH and the heat associated with the heater. But finding out what those flakes really are, is the key!

By the way, the photo above is what your Suburban inner tank might look like before it is glass-lined.

Microwave Troubles in Motorhome

I have an Apollo microwave oven in my Georgie Boy Landau motorhome. The microwave quit working. After putting in the time for microwaving I press the start button and yet the microwave doesn't start. What could the problem be? Does the microwave have a motor that runs it? Could the motor have quite working? It is an Apollo Half Time Oven made in 2004. Jim S. (Rockport, TX)

Unfortunately Jim, when it comes to microwave ovens, specialty diagnostic equipment is required. Being a "special" appliance of sorts, we do not even teach microwave repair at our RV schools. In warranty cases, the microwave is simply replaced. I'm not aware of any RV service center that actually troubleshoots and repairs microwave ovens. I feel it is has fallen into the "costs less to replace than repair" category. I'd recommend an Internet search for the closest servicing center for the Half Time and see if they can help. I’m sure they exist, just not within the RV realm in most cases. I wish I had better news, but other than verifying the incoming voltage, making sure it measures 120-volts AC +/- 10%,  it's one of those rare items that do not typically fall within the realm of RV repair. 

RV Slideout Manual Override - Where Is It?

We have a 27-foot Gulf Stream Streamlight trailer with a small slideout. The manual states that there is a manual override to retract the slideout in the event that the electric motor fails. We cannot locate the "emergency device." We even had a technician look with no luck. The motor is located in the middle of the sofa but there is no access to it. Any thoughts? John E., (Hartsel, CO)

John, the slideout motor used in the Streamlight brand is produced by Lippert, one of the largest providers of slideout mechanisms. All Lippert electric motors have an extended shaft with a cross pin that can be manipulated by hand to extend or retract a slide room manually. Some models may be equipped with a hex shaft in which case a ¾-inch box end wrench can be used. 

On your coach, below the sofa you'll find a kick plate covered with a fabric. There will be either two or more, medallion-like decorative pieces on that kick plate. They pop off easily with a flat blade screwdriver and then you'll see the attaching screws. Once you remove those screws, the kick plate will come off and you'll have clear access to the slide motor. Lippert ships a flexible adapter with each unit that can engage the shaft of the assembly in order to turn it by hand; probably the “emergency device” you mention. If you don't have that adapter, one can probably be easily fashioned. I'm not sure which direction you rotate the shaft, but you'll be able to tell once you start. Just be sure to only manipulate it by hand.

Two Flat Tires - One on Each Side of the RV

I have two flat tires on my RV, one on each side. How do I change tires on a travel trailer? How do I jack the trailer up to change the tire? Or is there a better way? Willie B., (Gulfport, MS)

Well a better way for me Willie, is to call one of my son-in-laws and have them do the work! But here's the next best idea...

Loosen the lugs on both wheels holding the flat tires while the trailer is on the ground. Always jack the trailer on the main frame rails only; never on the axle. As you raise the trailer, the suspension will relax and sag. Once the tires are off the ground, support the trailer on weight-appropriate (sized correctly) jack stands and remove/replace the tire assembly.

Always use safety jack stands. Do not allow the jack to maintain the weight while the coach is in the air. Chock the opposite side tires and be sure the tongue jack stays on the ground during the entire process. Change the tire on one side first, then the other side.

It’s best to use a floor jack, but a bottle jack is workable if it can be supported underneath and has enough reach to raise the tires off the ground. In some cases, you might have to use wood cribbing to build up the jack placement. It’s doable, but a hefty floor jack is better.

It's also wise to find out exactly what caused the flat tires. If there's no obvious cause (nail, faulty tire valve, etc.), a tire expert can inspect the inside of the tire casing and determine the exact cause of the failure; a little tire CSI! The main causes of tire failure are under inflation and overloading. Evidence will show if either contributed to the flats. You'll certainly want to rectify an issue if you possibly can, so as not to repeat the scenario in the future! 

RV Refrigerator Thermistor Positioning

We have a Norcold N841 refrigerator.  Please tell us where the thermistor should be on the fins. Roger G., (Florida City, FL)

Roger, counting from right to left, the thermistor should be attached to the 10th fin. (I love these short and to the point questions! But now what do I do with all this white space?)

Probably a good place to remind everyone to check the outside vent(s) for the refrigerator. Clean in and around the burner area and make sure nothing is blocking the vents through the side wall of the RV (as pictured), or the roof vent if so equipped. 

The rear of the refrigerator requires good air circulation! 

Frozen RV Holding Tank

How do I unfreeze a black holding tank on my RV? I'm not sure if it's full or not. The dump valve is froze shut also. I only need options for a stationary RV as I can't get the 5th wheel to a shop. Emergency!!!!!  Help!!!! Mike A., (Squamish, BC)

I hear your desperation Mike! Sorry to hear about your holding tank issues; so exasperating, I know! If you’re careful, you can use a hair dryer or heat gun to help thaw the tank. Don’t stay in one focused area for any length of time. ABS and polyethylene tanks can be melted quite quickly if the heat is too hot or you linger too long in one spot. Start at the uppermost level of the tank and work your way down all exposed sides of the tank until you reach the termination valve. Keep the gun in motion at all times. Repeat as necessary until you can open the termination valve and you hear contents evacuating.

Once evacuated, flushed and the valve closed, add a gallon or two of RV anti-freeze or even windshield washer fluid to the tank through the toilet. Be sure the strength is applicable for the expected temperatures though. And be sure it is RV anti-freeze and that the windshield fluid is permitted to be dumped into your septic system. If possible, see if you can add insulation around all sides of the holding tank. In sub-freezing temps, it is difficult, but doable is most cases to continue to use the on-board waste systems.

Unfortunately, the only other alternative I can think of contain the words “wait,” “spring” and “thaw” in it. If you have enclosed holding tanks, you can place a 100-watt trouble light inside the compartment to help keep it warm after you finally get it evacuated completely. Also consider purchasing an aftermarket holding tank heating pad prior to, say, next September.

How Are the RV Batteries Connected?

The two house batteries in my motorhome have been removed to be replaced. They were 6-volt batteries but the person who removed them does not remember if they were wired in series or parallel. The motorhome is a 2005 Cross Country. How should the house batteries be wired? Will S., (Seminole, OK)

Will, since all DC electrical components in your motorhome are powered by 12-volt battery power, two 6-volt batteries must be connected in series in order to provide a final, 12-volt output. Here’s another post that may be of help to you. Check this out.

 Also, FMC Magazine published one of my in-depth articles, "The Balance of Power," you might find helpful. Feel free to contact FMCA and request a copy of the January 2012 issue.