Charging house batts while driving

darsben1 wrote:
The solenoid is in exactly the same place as mine and mine is original

Thanks!
Trying to get his old MH working is slow but I'm making progress. Fixed a couple of battery issues, ordered new thermocouple and ignitor module for fridge and will be trouble shooting an intermittent water heater today. Then we need to seal the roof.
If there's time. Can't have him living on the side of my house any longer than today but I know where he'll be parked so I can replace parts when I get them.
Wish we had better for our vets.

Thanks again for everyones thoughts.

Scott

The solenoid is in exactly the same place as mine and mine is original

Thanks for all the great posts. I think someone has modified this rig. The Ford type solenoid has probably been added. All it does is connect all the batteries together. (I traced it all out and the relay looks alot newer than everything else)
The momentary switches over the door do work and are on but the bats still never connect together
I wish I had caught Robs post about the Intelitec sooner but we ran out of time and I had to do something....
So I disconnected the underhood light, which is controlled by a switch on the dash, and used that circuit to turn on the solenoid.
Now he can see if the batteries are connected and can do so when ever he needs to, regardless if the engine is running or not.
Not an entirely elegant fix but it's electrically sound.

Thanks for all your posts.

Scott

There should be a smallish box under the hood with an Intellitech Label and multiple small wires plugged into it! This is the Charge relay !

The Ford Solenoid is only for the Engine!

Perhaps this is closer to what you have. This is from a mid 90's Fleetwood. Hit ctrl + to enlarge pic, and ctrl 0 to reset.

Do not mix a starter relay with the charge relay.
The black box under the hood should have the battery disconnects, possibly an ignition relay that provides power to chassis items installed by Fleetwood and the charge realy.
I would verify that the realy with the large red wires in first photo is or is not a starter relay used ins ome years to enhance engine starting.

The "Ford starter solenoid" style is correct, but note that the solenoid used for battery isolation is NOT the same as the starter solenoid. The isolation solenoid is rated for continuous duty, where the starter solenoid is only rated for intermittent duty. I don't recall exactly what the earlier Fleetwoods used for the solenoid trigger, but the two most common sources are the ignition switched tie previously mentioned or an oil pressure switch controlled source. The ignition switch is the more common connection though. I've traced problems with "house" batteries not charging while under way to a burned out intermittent duty solenoid that had been used as a replacement for the required continuous duty solenoid on several occasions over the years. Of course given the age of this RV, even a continuous duty could easily have died as well.

I have a 1990 southwind on the chevy chassis
Short answer is the house batteries are charged while driving. Quite quickly too

Are the switches above the door on? They are momentary and control large solenoids in the electric control panel

Thanks everyone.
Yes it's like the old style Ford solenoid (oddly, it looks rather new).
There is no switch or button on the dash anyplace to trigger it.
All batterys have been disconnected, cleaned, watered, load tested and are totally charged but they still dont connect to each other even when the eng is running. The trigger wire disappears into a harness.
There is no diode based isolater unless it's under the panel shown below. (But thanks for the schematic Fultimin)
On the driver side under in the front, there's a large black metal box that says it some kind of central connection center. I'll probably open it up and see if I can find the other end of the trigger wire.

fulltimin wrote:
The relay that ties the 2 sets of batteries together, is only supposed to be used for starting. If the coach battery voltage goes low enough, that it won't start the engine, assuming the house batteries are in good shape, there is a button on the dash that will temporarily tie the two together, to help it start.

It is a momentary switch, and as soon as you let go of the button, the relay drops out and the 2 are separated again.

There is however, a black box near the batteries, (or should be) that the charging wire from the alternator goes into, and then it is split, so that both sets of batteries get charged at the same time, but will not backfeed into each other.

There is nothing to do, it is automatic.

There are various setups.

Sometimes the same relay is used both for the emergency start feature and to connect the batteries together when the engine is running, in which case it is activated by pressing the button or (typically) by a run circuit from the ignition switch. This is what my motorhome has, and it's pretty common but by no means universal.

Sometimes there's a separate or partly separate bidirectional relay thingy (aka BIRD) that connects the two together whenever one of them is above a certain voltage threshhold, which also allows the converter to charge the chassis battery.

Sometimes the charge from the chassis to the house battery is via a solid state isolator (a power diode), which has the disadvantage of introducing a voltage drop of about a half a volt or so in the charge circuit for the house batteries.