Kooky Cables
We have a 1986 Fleetwood Limited with three batteries. We need a diagram that shows how to hook up all the wires from the alternator to the battery isolator. For some reason, our cranking battery is discharging while the motorhome is being driven and is not being recharged.
Dennis Williams, F408252, Memphis, Tennessee
Since you write in your e-mail that your motorhome has three batteries, I’m guessing that you have a gasoline-powered coach. Two of the batteries are dedicated to the coach (house batteries) and one battery is left to start the engine. The problem could be as simple as a slipping fan belt. This is the all-time number one cause of this particular problem.
Here’s how to determine whether the belt is slipping. With the engine shut off, find the engine fan belt that drives the alternator pulley. If the belt has been slipping, it will have a glazed appearance. When the belt slips, it may not turn the alternator pulley fast enough to charge the engine starting battery. If this is the problem, have the belt replaced, not just readjusted. Also, most all V-belts on gas or diesel engines will stretch in length as they are breaking in, so a new belt may need to be adjusted after some use.
Another possibility is that the alternator itself is not working or that its output is not reaching the batteries. Check the alternator with a digital voltmeter — if operating properly, it should register 13.5 or higher volts. If the alternator is working fine, you will need to determine how the alternator is wired to the chassis battery. Contact Fleetwood for the wiring diagram that shows where the battery isolator is located.
House Batteries, Disappearing Coolant
I’ve read several reports and received opinions on how to handle house batteries when a unit is not being used for an extended period, such as two to three months or over a winter. I can’t remember what the recommendations were, so I need a refresher course.
Two years ago I parked my RV for the winter with the systems turned off. When I was ready to go in the spring, the batteries were dead but refreshed easily. Last winter I heard that if I had shore power available, I should leave the RV connected so the batteries stay charged. I did have to add water during storage time.
Everything started up okay for a May trip, but then we became unable to travel, so the motorhome was put back in storage and plugged in until August. Again, I did have to add water during the time in storage and, as always, had to wash the tray and tie-downs to get the crud off.
In August I took the RV in for some other service and asked that the batteries be checked and filled. The RV charger panel said the batteries were fully charged, but the real test at the batteries showed they were just at the poor range and would not charge above this level. The batteries are just shy of 4 years old, which seems short. I did replace the batteries.
So, is there a simple answer about keeping the motorhome plugged in or keeping it turned off? Is the answer different for summer versus winter? Is there an online report that I could access for a full story?
I also have another question about loss of engine coolant. Two years ago, the motorhome “lost” 2 gallons of coolant while it was stored outside in the winter in Union, Kentucky. Pressure checks, hose checks, and even engine oil checks were performed, but we could not determine where the coolant went.
This past winter I “lost” another 3 gallons of coolant in winter storage. The motorhome does not lose coolant in the summer when it is in use. This is the pink, extended-life coolant used in the Cummins ISL 400 diesel engine. A Cummins representative told me to check all the hoses and connections, which we did in the summer, and everything looked good. Two mechanics told me they think the coolant is evaporating through the cap; another thought the coolant was being used up, but that can’t be since I don’t lose any when the coach is in use. I’ve not seen any reports in FMC magazine where others find coolant loss during storage, but perhaps there have been reports not published or ones I missed. Do you have any comments or reference materials relating to this problem? This year any storage, whether short-term or long-term, will be inside, and the garage will probably be above freezing at all times.
Fred Leport, F370763, Union, Kentucky
Let’s start by addressing your battery problem. Batteries will normally last 3 to 5 years if well maintained. When not in regular use, the batteries should be kept charged with a staged charger that would not make the batteries gas excessively. They also should not be allowed to sit idle and completely discharge. A good charging system will top the batteries out and then drop to a maintenance charge of approximately 13.3 volts.
Now on to your coolant problem. It’s not unusual for an absolutely tight, no-leak cooling system to consume some coolant through evaporation, expansion, vapor discharge, etc. That’s pretty normal and to be expected. But you’re losing way too much coolant. One possibility is that when the metal contracts in cold weather, a leak occurs where the large-diameter hose connects. Once the metal warms back up and expands, the seal tightens and a pressure test does not reveal a leak. Constant-torque hose clamps or double clamps can help eliminate this problem.
If there are absolutely no hose or seal leaks, I would have an analysis done on the engine oil immediately for coolant contamination.
No-Start Suncrest
I have a 1990 Suncrest motorhome. A few days ago, I went to start my RV and nothing happened. So I charged my batteries and tried again; still nothing. The headlights and horn also do not work. I just had the alternator replaced, and it seemed to work fine. Do you have any suggestions?
Mary Rojas, North Highlands, California
My first thought would be that your battery has become disconnected. Perhaps when the alternator was replaced, the technician failed to secure one of the battery cables properly and it worked itself loose. Check all the connections to determine whether this is the problem. If all the connections are tight, remove the battery and take it to an auto parts store to have a load test performed. This will determine whether the battery is charged and strong. If the battery checks out, you will need to have the motorhome’s electrical system checked out to determine where the power interruption is occurring.
{loadpositionEndBlurbTechTalk}