fix one issue, find another

We have a 24 ft Minnie, same year as yours. Winnebago calls the solenoid that connects the house batteries to the alternator output the "Battery Mode Solenoid". I have replaced ours twice. Over time the solenoid sticks and doesn't pull in when the ignition is turned on, resulting in no charge to the house batteries when driving.

If you have a voltmeter, you can check the solenoid to see if the problem is with the solenoid itself or the wiring from the ignition switch.

Our Battery Mode Solenoid is located in an outside compartment, along with a number of breakers. The cover looks like this:


After removing the cover, remove the breaker panel. A word of caution here - there are lots of wires behind the breaker panel that have plus 12 volts on them. Be careful not to touch any bare connections to ground, or you will get an exciting spark (don't ask how I know).


The Battery Mode Solenoid is the silver thingy in the picture with two heavy wires and one light gauge wire. One heavy wire comes from the alternator and the other connects to the house batteries. The light gauge wire comes from the ignition switch. With the engine running, the light gauge wire and one of the heavy wires should both have alternator voltage - around 13-14 volts. The other heavy wire will have the house battery voltage. If the light gauge wire doesn't have alternator voltage, there is a problem with the circuit from the ignition switch. If the light gauge wire does have alternator voltage, but the house batteries aren't getting alternator voltage, the solenoid is stuck in the open circuit position. You might get the solenoid to pull in by tapping on it, but there is no guarantee that it would work on its own the next time you start the engine.

Welcome to the wonderful world of MH ownership. If your tires are showing cracks then replace now vs. later or a blowout. At that time get the correct valve stems.

To stir up a hornets nest IMHO you need new tires if your tires are over 5 years old no matter what the tread depth or the physical appearance. Also if you had one of the dual tires blow you need to replace the other dual tire on that side since it has been subjected to a excess weight load when the other tire blew.

Hairline cracks on tires is not a problem to me, if they get deep enough to see any cords inside then it is time to change the tire. Asking the tire shop if you need new tires is like asking a group of foxes to help design the security for your hen house. LOL

On the battery in the house, first check to see if the battery ground cable is making a good connection, also check the positive cable as well. A ground is easy to check, often by just adding a new ground wire to see if that solves the problem. Some of the convoluted ways the chassis makers ground house batteries makes me wonder at times. I have in the past run a second ground wire back to the chassis battery negative post. Make sure the battery post are clean of any corrosion and that the battery is good.

On my tow vehicle, a 2011 Chevy diesel with dual batteries, one wouldn't stay charged after the truck was about 6 months of age. I took it back to the dealer and the service manager told me that he had seen several trucks of that year with this problem. He asked me to wait a few minutes, had a mechanic get their battery tester on the one having the problems. In 15 minutes I was out of there with a new battery and the problem was solved. A battery working one day, doesn't mean it will work the next, in my experience.

naturist wrote:
(Solenoids move mechanical things, @tenbear; when they move electricity, they're called relays. A nit, I know, but good call on the cause.)

OK, its a relay, but it looks like a solenoid. Not to be confused with the starter solenoid, um relay.

Yeah, if you are seeing cracks in the sidewalls of tires, they are about to blow on you. Cracks say "this here rubber is old and hard and won't take flexing." Replace them now or plan on emergency roadside replacements (where they'll really cost you).

And I second the "look for a blown relay, probably under the hood somewhere." (Solenoids move mechanical things, @tenbear; when they move electricity, they're called relays. A nit, I know, but good call on the cause.)

You probably have a solenoid to connect the chassis battery to the house battery when the ignition is on. The solenoid on mine died and the house battery didn't get charged. Replaced it and all was well. Mine was located under the hood near the battery.

....it's amazing how often we find them low. this time, only 25 lbs in the rear outside discovering a faulty valve stem;...

What TYPE of valve stems do you have on the MH?

I won't go into details again about my experience but it centered around blow outs resulting from low tire pressure on the rears. Serious damage to my sewage bay from one of the blowouts.

WRONG valve stems on my couch. They were rubber.

Do yourself a favor and for importantly for 'safety' reasons have ALL the valve stems changed out to stainless steel as soon as you can.

Tire shops can do it in less than an hour. Small price for a big safety issue.

About the Tires. Sounds like you're on the way to a new set, or at least a few replacements. You said a key phrase "faulty valve stem." Please plan on getting better valves with your new tires. Top of the line is the dedicated, specially designed, custom valves by Tire-Man and Borg. Solid brass, made to fit, made to check and add air with any kind of gauge and any kind of chuck. Not cheap, just a little over $100, but they also DON'T LEAK! If you don't want those, at least get metal valve stems. Then you can use various extensions or extender hoses, as long as they're "airless" meaning they don't hold air till you press on their cores.

You're talking about the House Battery running low? Is it a good battery? If it's good, if it's turned on, then possibly.... The chassis alternator charges the house battery through a Battery Isolator. This thing allows the chassis to charge the house battery, but doesn't let the house systems draw the chassis battery down. They also usually include a start assist feature. This, usually with a dashboard pushbutton, allows the house battery to "jump" the chassis battery. If the Isolator isn't connected properly, or if it's damaged, then the house battery isn't getting charged till you plug into shore tie someplace and your Converter/Charger takes over.

Might have your batteries and alternator checked. Something is not right.
How about your battery disconnect switch?

Might want to replaced cracked tires before you have a blowout.