No 12V when unplugged from shore power

ke4jr · 02-25-2018, 06:52 PM

Today I unplug the MH from shore power and noticed my refrigerator was not working, in fact nothing was, no 12V at all. I plugged it back into shore power and all is well, everything works.
Unplugged it again, checked all the 12V breakers under the fridge, nothing tripped. Went to checked the voltages and shows no voltage on house battery but 13. on coach battery. Now I put a voltmeter on the house batteries and they are good...
Any thoughts, is there a main 12V breaker somewhere I don't know of?

rgvtexan · 02-25-2018, 08:14 PM

Salesman Switch? Battery disconnect.

Ranger Smith · 02-26-2018, 04:23 AM

There is also usually a big 300amp fuse right the + battery terminal.

l1v3fr33ord1 · 02-26-2018, 05:12 AM

ke4jr-

The wiring diagrams for your coach are available online here.

The 12V wiring diagram is this one. If you look at PDF page 2 (which is sheet 1 of 9 of the diagram), in the upper-right is the house battery diagram.

I have not spent more than a few minutes looking it over, but my diagnosis is that the house batteries are not charged.

Here is a test you can run. Unplug the coach from shore power and then try and start the generator. Report back with your results.

ke4jr · 02-26-2018, 12:35 PM

Not even to crank on generator

cbeierl · 02-26-2018, 12:49 PM

Quote:

Originally Posted by ke4jr

Not even to crank on generator

The generator probably starts from the house batteries, so that would be consistent with the house batteries being discharged.

l1v3fr33ord1 · 02-26-2018, 02:04 PM

ke4jr-

I bet the generator would crank over if the coach was plugged in.

Do you have a specific gravity tester for lead-acid batteries? That would be a way to see if they are healthy (without taking them out for load testing, that is).

megammon54 · 02-26-2018, 02:30 PM

I had a breaker go bad that was in the dash. It was a little push in breaker. Does your dash lift up? Mine was on left side under some fuses. I have a 98 Adventurer. Good luck!

tderonne · 02-26-2018, 02:34 PM

Did you confirm he disconnect switch is on/off (however you want to think of it)?

Simple to check it. House battery voltage when plugged in should be 13.X volts (converter output voltage). If your batteries are less, say 12.6, they are not connected.

ke4jr · 02-26-2018, 06:12 PM

I called my guy "RV Doctor" and after checking and the fuses, and breakers and removing all the panels under the fridge and under the bed, in front of the firewall under the hood, he sat on the driver's seat and pushed the AUX BATT switch ON, tried the generator and it cranked up, turn it off and when I heard that I hit the light switch and Lord behold, miraculously everything is working, all is good and angels were singing in my head!.
Apparently when I was cleaning the dash the other day I hit the AUX BATT switch and turn it off.
Man, I feel stupid, my first senior moment I guess, a first of many more to come brain fart.
I want to thank all of you who offered remedies, especially those who hit the nail on the head!

Sue46 · 02-27-2018, 04:25 AM

Our "salesmans switch" in next to the switch to keep the steps out. I kept hitting the wrong switch. I finally put a cover(made from a milk bottle) over the salesman switch. Haven't had a problem since.

l1v3fr33ord1 · 02-27-2018, 04:31 AM

ke4jr-

Glad things are working now.

However, by the wiring diagrams the AUX BATT solenoid and relay are not in the charging circuit for the house batteries. So, I'm not sure your problem is solved.

As a check, put the AUX BATT switch back in the position the "doctor" found it and see if you have 12V in the house.

ke4jr · 02-27-2018, 05:00 AM

After checking the manual the switch is designed to cut off power to all 12V for long term storage to prevent parasitic drain, kind of a battery disconnect switch which I think that's what it should have been called on the dashboard instead of AUX BATT, and perhaps I would have figured out sooner.
Again, thanks everyone!

l1v3fr33ord1 · 02-27-2018, 07:28 AM

It's interesting that Winnebago mounted the switch on the dashboard. On many coaches, this switch (colloquially known as the "salesman switch") is mounted near the entry door. "rgvtexan" in post #2 was right on.

I'm with you that Winnebago could have called and labeled it something like 'HOUSE BATT DISCONNECT," rather than "AUX BATT." A labelmaker would take care of that...