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Black-water blues, gooseneck-hitch guidance and a fridge fix

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July 10, 2012 by · 2 Comments 

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Tank Trouble

I have a 2003 Coachmen Aurora. I am the second owner of the coach, which was only a little more than a year old when I bought it, and I have had repeated problems dumping the black-water holding tank. This is my fourth RV, and I have never had any such problems before, so I doubt that it is a procedural thing on my part. I generally put in one to two gallons of water, add the holding-tank treatment, then add five to six gallons of water so there is little to no chance that solids and toilet paper could dry out and create a blockage.

Still, the tank clogs and will not drain after normal use. We also use paper formulated for RVs. It doesn’t seem to matter if the interval between draining is a week or only a few days, or whether we have driven the motorhome or remained in one place.

In all instances, I have been able to get the tank to drain after using a Camco holding-tank rinsing stick with a spinning brass valve inserted through the toilet and by forcing water at as much pressure as I can through a hose up through the open dump valve (that’s right, open—and this aspect makes the job most unpleasant) into the area where the bottom of the holding tank connects to the drainpipe. Because the hose has to pass through two bends in the drainpipe, I cannot get the hose and the water all the way up to where the clog is probably located. Therefore, it can take a couple hours of work before things break loose and the tank drains.

Once the tank has drained, I spray the inside of the tank with the Camco stick and fill and drain the tank several times until everything flows freely. I use Pure Power enzyme holding-tank treatment whenever I can get it; otherwise, I use Thetford products. Nevertheless, the problem recurs.

I think this could be a design problem with the drainage system on the Aurora, or, as some of my fellow RVers have suggested, there is something in the tank itself that doesn’t belong there. Perhaps plastic or a superfluous part was inadvertently left inside during manufacture. It would be a major production to remove or replace the tank, and I am hoping you have a better idea. As you can imagine, I am very frustrated with this situation and would appreciate any help you could give.

Barry Kasprow
Millsboro, Delaware

Bob: Barry, I admire your tenacity. Anyone who is willing to spend a couple of hours squirting water up the holding-tank pipes gets a gold star for good maintenance practices. As you might surmise, it’s difficult to diagnose a problem like yours without inspecting the holding tank and pipes—a procedure, as you suggest, that is not very pleasant. You need to see what’s going on, which is difficult because of the bends in the pipe. If the toilet connection drops directly down into the holding tank, you might be able to pull the toilet and use a mirror and flashlight to make a visual inspection. If not, you’ll have to drop the tank, pipe and fittings.

My first reaction was that the bends in the pipe are too severe, but even if that were the case, the flow would be better than what you are experiencing. So my long-distance guess is that something got lodged in the hole where the dump pipe connects to the tank. It’s possible that the hole was cut and the loose piece of plastic was left in the tank (or even partially cut and acting as a flapper valve). Maybe something was dropped into the tank during the manufacturing process and got wedged inside the pipe. Whatever it is, I would think that the obstruction would eventually work its way out, considering all the water you’re forcing into the area.

If the tank is between the belly pan and floor of the rig, the removal process will be time consuming and potentially messy. You might be able to avoid dropping the tank if you can convince a plumber to run a snake with a camera into the system in an effort to pinpoint the obstruction. This is not a cheap process, but it will probably show you what’s blocking the flow.

Towing a Tacoma

I recently purchased a 2007 Toyota Tacoma PreRunner. I would like to set this unit up to tow behind my motorhome. The owner’s manual recommends against dinghy towing this truck but does not give any explanation as to why except to say that damage will occur if the vehicle is towed by this method.

I would think that with a Remco driveshaft coupler, Roadmaster’s Add-a-Brake and the proper tow bar, this vehicle would be capable of being towed. The only thing I can think of that might be damaged by towing is the electric power steering. What are your thoughts on this subject?

Tom Hill
Marana, Arizona

Bob: The steering is not the issue. If it’s a four-wheel-drive truck, it is equipped with an electronic-transfer case that has no neutral position. Four-wheel-drive vehicles cannot be towed without a neutral position. The other problem is with the transmission. The rear wheels will turn the transmission, which will overheat because there will be no oil circulation without the engine running.

Your Toyota is perfectly towable on all four wheels when equipped with a Remco coupler and replacement driveshaft. Plan on spending between $700 and $950 for the parts and about three hours labor. Remco can be reached by calling 800-228-2481 or by visiting

Regular or Gooseneck Hitch?

I hope you can help me decide which type of hitch to use. Although we are longtime members of Good Sam and have been RVers for a couple of decades, we always had motorhomes or travel trailers. Recently, we purchased our first fifth-wheel trailer. We know very little about fifth wheels. Due to the question regarding hitches, we have not had one installed yet. Our tow vehicle is a 2005 GMC Sierra long-bed 2500 crew cab. It is powered by a Duramax diesel engine and Allison automatic transmission.

Some of my friends who own fifth-wheel trailers say the standard-type hitch is best. Others say the gooseneck type is the best. I am aware that the gooseneck type will leave the truck bed free of obstructions, and that does seem to offer an advantage. The standard types appear to be heavy duty and sturdier. Please advise of the pros and cons of each type. If the gooseneck is so great, why aren’t they installed on new RVs? Are there any legal issues raised when changing to a gooseneck?

Quinton Cable
Soldotna, Alaska

Bob: That’s an interesting question, Quinton. As you probably know, the gooseneck-type hitch is widely used on stock trailers and other farm/ranch/construction trailers. In order to maintain the versatility of work trucks, the gooseneck arrangement allows instant use of the entire bed when not towing.

The RV industry adopted the fifth-wheel setup commonly used by the semi-truck industry. All this goes back many years ago when fifth-wheel RV trailers first came on the scene. The RV industry dabbled in the use of goosenecks (from the factory) years ago when Holiday Rambler, for example, offered this type of hitch as an option.

There are a number of options if you need to use the truck bed for other chores when not towing. Gooseneck adapters that attach to the kingpin box on the trailer are available in the aftermarket. These adapters can put more stress on the front of the fifth wheel, and many trailer manufacturers do not recommend their use. Some trailer manufacturers will optionally beef up the front end, if you know you’re going to be adding a gooseneck adapter before ordering the trailer. Bottom line: Check with the manufacturer of the fifth wheel before making the conversion to a gooseneck.

You can also improve the versatility of your truck bed by using conventional fifth-wheel hitches designed for easy removal. B&W Trailer Hitches (800-248-6564,, for example, offers a unique mounting system in which only one hole is cut in the bed and a special mechanism is installed that accepts the company’s gooseneck ball or the fifth-wheel hitch. Removal and installation are easy, requiring a simple pull of a handle before lifting the hardware out of the bed.
Interchangeability of the hitches is very appealing.

Other fifth-wheel companies, like PullRite (Pulliam Enterprises, 800-443-2307,, have conventional-type hitches that mount on plates that are pinned into the frame using four holes in the bed. So it is possible to maintain the bed versatility without going to a gooseneck setup.

One last thought: If you decide on a gooseneck, try it out first on a sales demo because you may find it difficult to hitch up if you’re towing with a four-door or crew cab truck. There may be a visual impairment from the driver’s seat, especially if you are not tall. You can solve that problem by using a mirror.

Lights On, Fridge Off

We have a 1997 Pace Arrow motorhome with a Dometic refrigerator (model number RM3862). We can’t keep the refrigerator running on gas when we use any of the house lights or anything that requires battery power. It runs fine on gas until we turn on a light.

The batteries are new and kept fully charged, and we can’t seem to find the problem. Can you help?

LeRoy and Evelyn Higinbotham
Smock, Pennsylvania

Bob: The first thing I would do is check voltage at the house batteries using a multi-meter (not a test light). Make sure the lights are off and the refrigerator is running on LP gas. Once you get that number, check the voltage at the junction behind the refrigerator (accessible from the exterior door on the sidewall of your coach).

Now turn on the lights while checking voltage at the refrigerator. If you see a substantial drop, there’s a wiring problem. Your refrigerator needs a minimum of 10.5 volts DC to operate on LP gas. While your batteries are supposedly new, they may not be charging properly, which could present a voltage problem after running a few appliances and lights.

Your refrigerator should be wired directly to the house batteries via a nearby junction box and circuit breaker. Typically, the house batteries for your coach were mounted under the hood, but they could be under the entry steps. Once you locate the proper wiring and the source of power, you’ll need to check all the terminals for possible corrosion and/or loose connections. Make sure you also check the ground wire.

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2 Responses to “Black-water blues, gooseneck-hitch guidance and a fridge fix”
  1. Larry says:

    I have a 1999 Jayco 32 foot RV. The refrigerator shows LOW AC when running. Doesn’t matter if the air conditioner is running or not. If I run the generator the fridge works fine. If I run the fridge directly from another separate receptacle (drop cord) the fridge still says LOW AC. What could be wrong?

  2. Dan Owen says:

    After reading about the black-water problem I needed to respond.
    My 1993 Shasta had the same problem, but both black and gray-water would drain slow. After about three years of fiddiling around I found in the tanks the cut outs for the tank access holes. I then had to remove the outlet lines from the tanks to remove them.
    No more problem.

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