12 volt system dead 2002 Minnie 331C

[Outlaw]

Good day all
So, let me just start by saying...the last 3 years I have sucked at maintenance, that being said we own a 2002 331c minni winnie...no DC power to coach AC is fine remove shore power and dead. 2/ 12volt batteries both at 12.97 amps, to me the disconnect solenoid seems a little suspect when hitting the aux. switch sometimes it clicks and sometimes it doesn't. (1) is there supposed to be voltage at the two large terminals when aux. is engaged?? I've traced the wires as best I can inside and outside even so far as to remove the whole power distribution panel , and I'll be damned if I can find this "300 amp" fuse i keep hearing about...(2) any ideas as to where it might be?? Should be fairly close to the batteries i would think. Any suggestions one may have would be greatly appreciated.

[creativepart]

Hi and Welcome.

Here's a link to the wiring diagram for the 2002 Minnie 331C:

https://www.winnebago.com/Files/File...ire_138099.pdf

Here's an FYI, Winniebago has 18,972 odd Winnie, Minnie, Mini, Minnie Winnie etc names for the their RVs. It's nuts. No one seems to know the "real" name.

Since yours is a Class C you'd think it's a Minnie Winnie (there are no Minni RVs). So, when I looked for your wiring diagram I found both Minnie (300) and Minnie Winnie (400) Class C motorhomes. That's a new one on me. The only 331C is a "Minnie."

My guess... and it's just a guess is that the 300 Series is based on the Ford E350 chassis and the 400 Series is based on the Ford E450 chassis.

Here is the listing for 2002. I don't know how many years it was like this - it's not this way now. Your RV would be a Minnie Winnie in current nomenclature:

Minnie (300)

• WF322E
• WF322R
• WF324F
• WF324V
• WF329B
• WF329N
• WF331C

Minnie Winnie (400)

• WF427P
• WF430V
• WF431C

So yours is a Minnie. Not and Minnie Winnie (nor a Minni Winnie).

[l1v3fr33ord1]

Outlaw-

First off, welcome to winnieowners.com!

Second, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

Re: 12V. The best way to track down 12V problems is with a voltmeter or 12V trouble lamp, starting at the batteries.

- Disconnect from shore power
- If your Winnie has solar, turn off the solar controller

These two steps ensure that you won't have any 12V charging current.

- Apply the voltmeter to the house batteries. Record the reading.
- Follow the positive wire lead from the house batteries to the Battery Mode Solenoid. Apply the voltmeter to the large lug to which the cable is attached. Record the reading.
- Follow the cable from that large lug to the Battery Disconnect Relay (solenoid). Apply the voltmeter to the large lug to which the cable is attached. Record the reading.
- Apply the voltmeter to the other large lug of the Battery Disconnect Relay. Have someone press the AUX switch. Record the reading.
- Have them press the AUX relay again. Record the reading.

That's enough steps for now. If you consistently get 12V through the Battery Disconnect Relay, we'll look downstream for the problem source.

Unless your Winnie has an inverter, there will be no 300A fuse.

Wiring diagrams for your coach are online, here. The batteries, solenoid and relay show up on the "Body, 12 Volt Wiring Diagram," page 4, which is sheet 1, on zone A-12 (link here).

[Outlaw]

Absolutely correct...just a minni, however it being a wf331c, it is on an E450 chassis

[Outlaw]

Absolutely correct on the minni...that is what it is a minni. However, being a wf331c it is on an E40 chassis

[Outlaw]

Ok...12.97 vlts at both batteries
.79 at mode solenoid and .77 at disconnect solenoid
Aux bat switch does not seem to activate the solenoid and seems to have no power...checked continuity at switch ...all wires good.
Always has continuity between large posts on disconnect solenoid.
Decided to jump directly from battery to the house side of this solenoid and viola...dc power on.
All tests done with no shore power/battery(s) on.
What do you think solenoid?
Pretty tough to follow wires when all the wires are yellow, some white and the odd black...must have got a good deal on the wire. Lol

[Outlaw]

Thank you for the help guys

[creativepart]

Originally Posted by Outlaw

Absolutely correct on the minni...

Yes… it’s a Minnie. M I N N I E

Curious what the difference is between the 300 series and the 400 series if it’s not E350 and E450??

General Winnebago practice is Yellow is 12v Positive and White 12v Negative. They do throw in some black wires sometimes, too But Yellow is positive.

The solenoids do fail occasionally. Generally there are two solenoids. One on the house side and another identical on the chassis side. Between is a latching solenoid that combines both sides: 1) when you start the RV so that the alternator charges both sides 2) when the Aux start switch is pushed.

Without 12v power the house and chassis solenoids will not function.

Be aware on some models the house battery cutoff switch is on the dash and is labeled Aux Battery. This is different from the momentary switch labeled Aux Start. I do not know if this applies to your RV. I just noticed you used the wording Aux Battery. If you have both Aux Battery and Aux Start switches in your drivers compartment make sure the Aux Battery switch is on or there will be no house 12v power.

Again, this does not apply universally. And Winnebago changes this wording all the time.

[Outlaw]

Ya, I dont know what the difference would be...it makes sense how you think it should be.
My aux. start is over on the left side of the dash, and my aux. batt is just above the batteries as you walk in the coach door. Thanks for the yellow wire info...makes a little more sense now.
Appreciate your help.

[RV Tinker]

I bought my Minni in 2004. The 300 series were not a basement model. I believe the 400 series had a basement and were a bit more upscale and more expensive. They stopped making the Minni around 2007 but could have been several years later. I still have the brochures from 2004. Just for grins I may try and find them and look at the differences.

[Outlaw]

RV Tinker,
It seems like Winnebago is a bit confusing...I believe that mine being a 331c would be a 300 series, however it is a basement model...idk if it has upgrades or not but it does have the fancy day/night window shades. lol
Also, as an update to my issues with the 12 volt system with the advice from the replies ...i determined that it was the battery disconnect relay...replaced it and everything works now...thank you all so much.
Geo.

[Morich]

Late for this problem but perhaps some ideas of how we might get more info for the "next time"?
Winnebago uses a code stamped on the small wires to ID them.


When looking at the drawings or finding the ID on the wire we can then go to the chart to "decode" where that wire comes from and to which often will tell us if it is power or ground, etc.
https://www.winnebago.com/Files/File...ical_guide.pdf

But there may be some confsuion on what part you are speaking of? The control witring for the solenoid will br LR with FM being an added ground if it uses a four wire/ four post solenoid.
But if you are speaking of a relay, the wiring WILL be different.

On the mode solenoid which is the big shiny silver for most, there should always be battery voltage on each of the big lugs at the sides, one side coach, the other chassis.
When we start the engine or push the dash switch 12Volt is sent down LR to operate the solenoid and connect left and right big posts, and batteries, together!

But if the solenoid is back behind the breaker panel, we can often test it better at the batteries. Test one set of batteries and then the other, noting the different voltages. Then when we push the switch, those voltage shoud read the same as they are connected! Super simple and quick way to test the solenoid without taking the RV apart!


The red is chassis battery, green coach battery, with the small control wiring marked in blue? One thing to be aware of is that there are often small wiring the feed power to breakers and DO NOT go through the battery disconnect switch as they are on the left side of the relay! This is where we may be fooled into thinking we have disconnected aLL the drains by opening the relay. NOT true as the safety items come off before the relay!