Charging house battery from engine

[skes]

On our way back to MI from a six week adventure in the SW, we did some boondocking. After several days on the road ,we ran the house battery down to the point I couldn't start the generator and had to overnight in a campground for some AC power (house batteries were back to 100% by morning). Once we returned home, I confirmed with a multi-meter that the engine is not charging the house batteries. As a first step to resolving the issue, I wanted to draw on the expertise and knowledge of the folks on this forum. Thanks in advance for any thoughts and ideas I can pursue further.

2006 Winnebago Sightseer 29R

[BobC]

There's a solenoid that controls this and its failure is the most common reason for your problem. This thread should help you sort things out, even though it references a different model/year than your's:

https://www.winnieowners.com/forums/...ing-59144.html

[davismills]

I agree with BobC that your solenoid is probably kaput.

My "boost switch" also known as the emergency start switch was a three-way rocker switch versus a normal two-way switch. When mine was in the middle position I was not getting a charge to the house batteries. Clicking it into the full down position resumed the charge.

It's worth a look before you replace the solenoid. I think mine was a fluke at the factory.

[JoeC]

Before you go ordering or removing the solenoid, check the function of your "battery boost" or "emergency start" switch. This is how many of these battery interconnect solenoid circuits function. If everything is set up and working properly, just turning the ignition switch to full on, not accessory, the interconnecting solenoid should pick up and is loud enough to be heard, especially if uncovered or if someone is stationed near it when actuated. This is how the batteries are interconnected and charging off the alternator while you are driving down the road. The "battery boost" if that what yours is labeled can manually energize the solenoid when the ignition switch is not in the "on" position, when depressed. There are two sources of power going to this switch, one is battery 12 VDC and the other is ignition 12 VDC. Battery voltage is routed through the switch when manually depressed and ignition voltage is routed through the boost switch in the un-switched position.

If only one function works, you may have a blown fuse for that circuit, battery or ignition power. If none work, you have two blown fuses, a faulty or disconnected battery boost switch, or a dead or disconnected solenoid circuit. That should do it.

[Chuckmor]

Had the same problem with my 2000 Adventurer. I replaced the solenoid, but found that there was no 'activator' current (not sure of the term) to make it close to allow engine alternator to charge the house batteries. Turns out it was the fuse for the Coach Heater, the blower of which was frozen up and therefore would always blow this fuse. The fuse is in a fuse block under the dash hood on the left side.

Until recently, I had never known what that Coach Heater switch did. But it's a great idea. When I discovered a detailed way to access and fix the blower, I spent several hours trying to get at it and get it out. (I had issues with the water heater anyway). I got at it, but was not able to get it out, so I abandoned the project. I had gone for years without it anyway.

So if this is your setup, replace the fuse and don't use the Coach Heater switch.

[Fletcher0077]

Originally Posted by Chuckmor

Had the same problem with my 2000 Adventurer. I replaced the solenoid, but found that there was no 'activator' current (not sure of the term) to make it close to allow engine alternator to charge the house batteries. Turns out it was the fuse for the Coach Heater, the blower of which was frozen up and therefore would always blow this fuse. The fuse is in a fuse block under the dash hood on the left side.

Until recently, I had never known what that Coach Heater switch did. But it's a great idea. When I discovered a detailed way to access and fix the blower, I spent several hours trying to get at it and get it out. (I had issues with the water heater anyway). I got at it, but was not able to get it out, so I abandoned the project. I had gone for years without it anyway.

So if this is your setup, replace the fuse and don't use the Coach Heater switch.

I never fixed min either. But did disconnect the switch to keep the fuse healthy.

[US1]

Originally Posted by Chuckmor

Had the same problem with my 2000 Adventurer. I replaced the solenoid, but found that there was no 'activator' current (not sure of the term) to make it close to allow engine alternator to charge the house batteries. Turns out it was the fuse for the Coach Heater, the blower of which was frozen up and therefore would always blow this fuse. The fuse is in a fuse block under the dash hood on the left side.

Until recently, I had never known what that Coach Heater switch did. But it's a great idea. When I discovered a detailed way to access and fix the blower, I spent several hours trying to get at it and get it out. (I had issues with the water heater anyway). I got at it, but was not able to get it out, so I abandoned the project. I had gone for years without it anyway.

So if this is your setup, replace the fuse and don't use the Coach Heater switch.

Coach heater switch.....
Are you referring to the dash heater/vent/AC control or the rear heat Hi/low switch on the dash?
Thanks

[Chuckmor]

Originally Posted by US1

Coach heater switch.....
Are you referring to the dash heater/vent/AC control or the rear heat Hi/low switch on the dash?
Thanks

I think it would be the rear heat Hi/Low switch. Mine is called Coach heater.

[skes]

Thanks for all the good info. I'm about to dive into trying to get it charging again. I was wondering what if anything bad might happen if you were to temporarily connect a set of jumper cables between the engine battery and coach batteries while the engine was running? For me this would only be used if the coach batteries were to low to start the generator - so, just use this process long enough get enough of a charge to start the generator. Certainly, fixing it is the best course of action but I like having a Plan B in a pinch.

[Morich]

What you propose is fine but it may help to understand why as there may be an easier way if some things are working while others not.
What the talk is about is that there is the battery mode solenoid and there is one single wire coming from the dash area down to the solenoid where it goes through the coil/winding on the solenoid to pull it up much like a big switch that you might flip. That solenoid connects the positive side of the start battery through to the positive side of the coach batteries. Just like a "jumper cable", except there are two ways this one wire gets power and that gets lots of confusion going!
When we push the "boost switch" or whatever your dash switch is called, it connects power top the control lead for the solenoid and it connects two battery strings together.
But when that momentary switch is not pushed and no power is sent to the solenoid, we can also make the solenoid work when we start the engine as part of the chassis wiring provides the power down the same wire to the solenoid and does the same thing---when things are working right!
So before breaking out the battery cables, if you start the engine, it "should" connect the batteries together. But you are thinking this is not working, but if you leave the engine running and push the boost switch, it uses power from a different source and may still be working!! I favor going the easy way first to see if that works before breaking out the cables!
But if all else fails, it really could be the control wiring, since neither way is doing it or it could be a bad solenoid itself. That is when it is still okay to use a jumper cable to tie the positive of the start battery to the positive of the coach batteries as that is really all the solenoid is supposed to do.
No need to connect the negative/ ground side of the batteries as they both are run to the same ground and if those cables are clean and connected to the frame ground, adding the jumper to them is not needed as they are already connected together. Doesn't hurt if you do it but just not needed?
Something you might expect, if it happens, is a few sparks if you connect a really charged battery like 12-13 volts to one which is less charged like 10 volts, you may get some sparks as the cables are connected, just normal, though.

[Chuckmor]

Originally Posted by skes

Thanks for all the good info. I'm about to dive into trying to get it charging again. I was wondering what if anything bad might happen if you were to temporarily connect a set of jumper cables between the engine battery and coach batteries while the engine was running? For me this would only be used if the coach batteries were to low to start the generator - so, just use this process long enough get enough of a charge to start the generator. Certainly, fixing it is the best course of action but I like having a Plan B in a pinch.

If you have a boost switch on the dash, holding that down connects the two batteries together and you can start the generator that way (or the engine battery if need be). As mentioned, at the solenoid there is a little wire coming from the ignition that when energized (12v coming when the ignition is turned on) it should activate the solenoid and connect the two batteries. If you have 12v there and nothing happens, the solenoid is bad. If you don't have 12v there, run a little wire from any 12v source and touch the terminal on the solenoid. If the solenoid connects, it's good. Then just find why no 12v from the engine. Most likely a fuse. As I said, mine was the same fuse for the coach heater. Good luck.

[Morich]

Originally Posted by Chuckmor

If you have a boost switch on the dash, holding that down connects the two batteries together and you can start the generator that way (or the engine battery if need be). As mentioned, at the solenoid there is a little wire coming from the ignition that when energized (12v coming when the ignition is turned on) it should activate the solenoid and connect the two batteries. If you have 12v there and nothing happens, the solenoid is bad. If you don't have 12v there, run a little wire from any 12v source and touch the terminal on the solenoid. If the solenoid connects, it's good. Then just find why no 12v from the engine. Most likely a fuse. As I said, mine was the same fuse for the coach heater. Good luck.

Agree with this but also want to throw in that we often forget we need ground also. On this solenoid the power comes in on the wire labeled LR but also has to have ground on wire FM to pull the coil in the solenoid. FM is often on the mounting screw so you get ground both from the screw and the wire but check it is there before assuming the solenoid is bad.
The chassis battery comes in from different spots on different RV but in yours, it comes in on a number 6 black wire on the left and the coach battery is setting on the right, so it also requires your battery disconnect relay but if all other things are working we can assume that part is okay---we thinnk!
What we can get if we take it to a hammerhead shop where they don't check for OUR specific RV is that they know how it works on another RV but miss something simple like the ground being corroded and they change out the solenoid for no reason!
Click this picture for better view if on a PC or go to the drawing here:
https://www.winnebago.com/Files/File...ire_153527.pdf sheet 1!