Alternator Charging 1993 Minnie Winnie DL27RQ Class C

[Brint S.]

1993 DL27RQ on Ford chassis. There's a 3-position toggle switch on the dash that does not seem to charge the coach battery with the alternator while the engine is running when switched to "Duel" (according to the Renology battery monitor). Im not even sure where to begin with this. Doesn't seem to matter if the power center circuit breakers are on or off. According to wiring diagrams from Winnebago, wiring is tied into Kwikee steps which do not seem to be operating as they should (with wall switch on or off). Any thoughts?

[creativepart]

Welcome!

Not many of us have first hand knowledge of your 31 year old motorhome.

But here’s a brochure showing the 1993 Minnie Winnie and hopefully provides some useful info:

https://library.rvusa.com/brochure/9...eWinniebro.pdf

[Morich]

Kind of the standard Winnebago system but less automatic than newer uses. You have to do the button to tie them, while later models do it auto when the engine starts!
You have a link to a fuse that brings power to the dash switch. when that switch closes, power is sent down a wire LR to the coil that controls a set of contacts in a solenoid. Power goes through that coil to wire FM and to ground. That makes the contacts inside the solenoid close.

On one side of this solenoid, there is a cable bringing 12volt from the chassis battery and on the other side big lug there is a cable to the coach battery!
That solenoid and contacts is where the coach gets connected to the chassis and alternator to charge while driving.
Click these snips for best view!
somewhere on the RV there may be a label that says "solenoid"! This is a picture of what is in there! The purple wires are the control wires. LR to bring battery to the small post and FM is ground and connected on the mounting screw as well!
Those are what make the solenoid close the contacts to connect the two big lugs with coach and chassis battery cables together!
If you are getting 12 volt down to this solenoid, you may hear it "clunk" or feel it if you put a hand on it as somebody pushes the dash switch! Purple marked small wires make red and green connect together!

This is the drawing in a different way (schematic?) that shows the wires a little better than the picture!

If the solenoid is not moving, maybe the 6 amp fuse that feeds power to wire LS is blown? It has to feed 12volt to the switch. The switch when pushed right passes that 12volt to LR and down to close the solenoid!

This can be a trouble spot as the contacts in the solenoid may move to close but they get burned over time and may not actually pass the power on through!
If you have a voltmeter, you should find 12volt coach on one big lug and 12volt (more or less?) on the chassis side. Usually not exactly the same but when the solenoid closes those voltages should match! If you rev the engine the chassis side will go as high as 14 or so when they are not connected. When the switch is closed and they connect, you then should see that higher voltage on both sides!

Gotta go for now as I have a call coming and I pretty well have to do it as business!
I will check in tomorrow, so take a look and see how this looks in person!
Sometimes what I see on drawings is not what it looks like in person, so take a look!

If the solenoid is bad, lets talk about what it needs as they are not hard to find but some better than others! First you want to make sure it is what you need, so maybe some testing?

[Brint S.]

Thank you SO much!!! I now have a good starting point for testing.

[Morich]

When you get into the wiring on Winnebago, they have done some things that help us sort the problems.
I assume it is true for the older, so check before trusting!
One is the way they label wires for ID:
Battery cables?
Tape wrapped at the cable ends. These are a question when the cables get older and the tape falls off or new cables used! But a hint if it is there!

Smaller wires like LR and FM?

When you find an ID on a wire or on a drawing, it can then be "decoded" with this chart:
https://www.winnebago.com/Files/File...ical_guide.pdf
This gives color and gauge of wire, then the "from" and "to" locations. That often tells you if it is battery or ground but at least does hint at where to find the other end!

A bit of side info that can help at times? They tend to use the single letter ID for wires that do more?
Like J or K?
Those two carry power to other places like other fuse panels. Big stuff to feed the smaller circuits with smaller wires! Then the smaller wires often use more letters! That gives a hint of what "importance" a wire may have?
Lose power on J and lots of things stop working, but lose power on KKK and fewer things may go dead!

Not a firm thing to trust too far but at times it can help. I think of it somewhat like a bunch of hoses in the yard? If the big hose at the faucet is dead, no use to wander around looking at the tiny little dripper hoses way out in the end of the yard? Gotta get the water in the first big hose before it comes out the tiny one at the end!

[Brint S.]

I can't thank you guys enough for the information. I'll post the solution just as soon as I get around to testing/tracing wires. Multimeter in hand-waiting for the rain to quit.

[Morich]

HA!
The mention of rain made me look at where you might be located. I remember what rain used to look like when we lived in Ballwin! The memory of those nice cool days with rain are almost faded from living in this future desert!