I have an 87 Barth Regal 32. In battery compartment are two 4-post solenoids, controlled by two footwell switches. I need to know what the solenoids are supposed to do, because the original wiring has been changed multiple times. I also need help identifying the cables that terminate there, as I am not sure what cables are inputs from genset, converter and alternator vs output cables to coach 12v systems. I have traced the footwell switch wires and they work, supplying 12v to one small post (switching circuit) of solenoid. I am told the other small post is only used on certain old Fords and not relevant, as the solenoids ground through the mounting base.

So the footwell switches turn the solenoids on and off, no problem there. But what cables attach to the power circuit posts (switched circuit), and which side? I know I have 12v coming in from converter/shore power on one large gauge red cable, one of the other large red cables may be from genset (currently inoperable, so can't test), unless genset goes through converter first, guess the other is from alternator (also currently inoperable, both because bad alternator, and the last RV tech who didn't know how to wire solenoids also disconnected coolant lines to water heater, so I get a flood when I start motor. Solution pending). That leaves one 10 gauge red cable, is this coach 12v power? I can wire the converter input directly to coach batteries, or on opposite side of solenoid. Same for the 12v output to the coach, I just need to identify wires, and what purpose the solenoids serve, so I can figure out which side of solenoid each cable belongs.

I am getting a strange noise (like miniature ray guns, piong, piong) from my monitor panel, which I think may be some sort of alarm to warn against overcharging or depleting batteries, but I am clueless here. Previous owner evidently bypassed solenoids entirely and charged batteries through converter on shore power, as that is the only system that works. But converter overheats and switches off after a few hours, so even that only works intermittently.thanks...jon

A real can of worms! There is so much variation in wiring, between what Barth did and then the owners did later, makes it hard to know where to start. I'll give you my best guess.

Generally, the convertor has a hardwire to the coach batteries to charge them. The alternator has a hardwire to the start batteries to charge them. Sometimes a diode splitter is installed in this alternator wire to allow the alternator to also charge the coach batts.


Other times, there is a solenoid switch installed to manually connect the positives of both sets to allow tandem charging, or "jumpstarting" when starter batts are low. I suspect one of the solenoids was doing this at one time.

The generator usually has a hard wire to the coach batts for the generator to start, then feeds back to charge the coach batts when the genset is running.

I'm not sure why there are 2 solenoids. Also the Ford type solenoids you describe are starter type solenoids. They are not designed for constant duty but are fine for "jumpstarting," etc. I will try to find some wiring diagrams but they are minimal at best. Good luck, hope this helps.

Found a diagram for an 84, might be similar?

Here's mine.

On your converter over heating. There is an internal fan in the converter, make sure it running. I ducted an external fan on mine to keep it cool. Ours has a 70 amp converter. Puts out lots of heat. So much I have thought about venting it to the outside.

Just like to remind folks that the Ford type starting solenoids come in two flavors. Intermitant and constant. I doubt if Ford actually used the constant duty ones for starting. So just make sure you have the right one.

My '92 breakaway has two solonoids...I believe one is a 12v master that is controlled by a switch on the wall by the door... And the other one connects all the batteries together for extra starting power controlled by a momentary switch on the dash...

The momentary switch on my Barth "works" but never gets enough juice to help start. I just use some short jumper cables I made to jump from the coach batteries to the starting batteries. Always worked.

Thanks all for your help. I do not believe 4 post solenoids are original, but one mechanic said buy 4-post so I did. He thought the second post was ground for switching circuit, which I now know it is not. Since neither the alternator nor the generator works, I can not look for voltage on those supply wires. Converter fan is not working, so it overheats, don't know if fan is available, but willing to invest in new converter if not.

Still not sure what footwell switches are supposed to do. Do they isolate coach/start batteries to avoid depleting them (switched output off)? Do they connect converter/generator output to coach/start battery to charge them (switched input on)? Does genset supply 12vDC? Or does genset output of 120vAC go thru converter to charge batteries and power 12v coach systems?

The good news is I found and fixed the coolant leak, so I can at least start the motor without a flood. The RV mechanic who installed the new water heater missed one of the coolant lines that once fed the water heater. I can charge the start battery by connecting my one good supply line (converter on shore power) to it, waiting for my mechanic buddy to finish his projects so he can replace my alternator. Then I will be able to identify that supply line in the battery compartment.

Also on the list is getting genset fixed. Then I can identify it's supply to battery compartment. At that point, if I can't discover what footwell switches do, I will decide what I want them to do and wire them accordingly. But with so many things inoperable, and previous owner's/mechanics mistakes added to my ignorance, it's hard to proceed with repairs.

quote:

Still not sure what footwell switches are supposed to do. Do they isolate coach/start batteries to avoid depleting them (switched output off)? Do they connect converter/generator output to coach/start battery to charge them (switched input on)? Does genset supply 12vDC? Or does genset output of 120vAC go thru converter to charge batteries and power 12v coach systems?

I'm not sure what you mean by "footwell switches"...

The genset powers house 120VAC and the converter charges only the house batteries. Depending on the type of converter (single- or dual-output), the converter will charge the coach batteries (single-output), which then supply 12VDC, or one section of a dual-output charges the house batteries and the other, separately, powers the house..

Good morning, Jon;

Regarding the "footwell switches," is this something like an old left foot operated headlight dimmer switch or high beam-low beam switch? Is it in the driver's left foot area where a clutch pedal might have been located in older times? If so, you might want to look under your motor home at the back end of your automatic transmission.

Jon, there is the possibility that you may be the proud owner of a genuine Gear Vendors 22% overdrive on your motor home. (You lucky dog. I am appropriately envious. Mine is not installed yet.)

If you do have an overdrive after your automatic transmission, that foot switch is probably for manually ("pedally?") controlling the in-out or high-low setting on the overdrive. You have control of the overdrive so that you can use it on all three forward speeds, yielding a six speeds forward transmission system. That "2nd gear Over" setting is really nice for climbing hills. The use of an old type foot operated headlight dimmer switch is one common way to shift the overdrive.

Enjoy; Ralph, Latte Land, Washington