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Hermes2 · 07-02-2022, 06:03 AM

So, I've got a 12 Volt Electrical Problem on our 2021 WBGO Adventurer 29B Class A.

Symptoms: Turn on Chassis Batteries at salesman switch but NO 12 volt throughout coach, except for dash 12 volt socket.

Batteries are fully charged (solar). Checked fuses, breakers, and battery connections; all seem good.
I can hear the battery disconnect relay "click" when the switch is used. The relay is behind the breaker panel in the drivers' side first compartment.
Connected to shore power. No 12 volt, but do have 110 to TV, Microwave, etc.
Started generator OK. Still no 12 volt, but do have 110 to TV, Microwave, etc.
Downloaded all wiring diagrams. Researched and found that relay is a Tyco 1-1414939-4 Battery Disconnect Relay. Ordered the replacement as I "think" it might be a bad relay (I'm not comfortable jumping the relay as it's in a awkward spot for me to get to and I'd hate to make the situation worse).

Any other suggestions for a possible fix would be deeply appreciated!

twinboat · 07-02-2022, 06:19 AM

Salesman switch is for house batteries.

Are you turning on the correct batteries ?

DavidEM · 07-02-2022, 07:13 AM

I recognize that the OP confused chassis with house batteries and he certainly meant house. If the house batteries were fully charged (but how did he know that?) and the salesman switch was on, then he should have 12V throughout the coach. The 12V at the dash socket is probably supplied by the chassis battery.

Soooo, the most likely culprit is the latching relay that is triggered by the salesman switch. The relay seems to be actuating because he hears a clicking sound. But it probably isn't latching correctly or its contacts are burned. The solution is to replace it which he is doing.

Should solve the problem.

David

Country Road · 07-02-2022, 07:24 AM

Quote:

Originally Posted by Hermes2

So, I've got a 12 Volt Electrical Problem on our 2021 WBGO Adventurer 29B Class A.

Symptoms: Turn on Chassis Batteries at salesman switch but NO 12 volt throughout coach, except for dash 12 volt socket.

Batteries are fully charged (solar). Checked fuses, breakers, and battery connections; all seem good.
I can hear the battery disconnect relay "click" when the switch is used. The relay is behind the breaker panel in the drivers' side first compartment.
Connected to shore power. No 12 volt, but do have 110 to TV, Microwave, etc.
Started generator OK. Still no 12 volt, but do have 110 to TV, Microwave, etc.
Downloaded all wiring diagrams. Researched and found that relay is a Tyco 1-1414939-4 Battery Disconnect Relay. Ordered the replacement as I "think" it might be a bad relay (I'm not comfortable jumping the relay as it's in a awkward spot for me to get to and I'd hate to make the situation worse).

Any other suggestions for a possible fix would be deeply appreciated!

On a coach that new, I would think your problem is a switching problem. You say no 12v thru coach. Does your ac work? How about your vent fans or toilet if electric? If answer is no, they don’t work, it sounds like your master 12v isolator disconnect switch is off or malfunctioning. The salesman switch operates only non essentials like lights, radio, etc.

BCam · 07-02-2022, 07:41 AM

You might want to post your IRV2 login. At Winnieowners you'll be in contact with a ton of Winnebago owners including owners of your particular MH.

I belong to both and find Winnieowners to be the best for Winnebago-specific issues and IRV2 for more general issues and chassis-specific issues.

In the meantime here's another source for a complete battery disconnect. Go to your parts catalog (choose your SN range):

https://catalog3d.winnebagoind.com/menu/Parts.htm

Then select "Electric", then "Chassis Wiring". You'll see both your house batteries and your starting battery in the diagram. Double click on the house batteries to enlarge the picture. You'll see two large fuse holders, colored blue. One of these fuses could be bad.

You can check them in place with a multimeter (shore power and generator "off"). You should show full 12V DC voltage (12.6V if fully charged) from both sides of each fuse to ground if they're good. Alternatively, if they're good, you'll get 0 volts between the two sides of each fuse (12.6V if they're bad).

Hermes2 · 07-02-2022, 07:50 PM

OP here. I meant Coach/House battery disconnect switch. This is also posted to the WBGO site.

Checked house batteries with voltmeter and through solar charge panel, which indicates FULL, 13+ volts.

No internal 12 volts means no AC, fans, lights, fridge, water pump, power center, etc.

The 12 volt dash socket DOES work, and is controlled by the Coach/House battery switch. I've no idea why that works but the rest of the system does not.

Yep, went to WBGO site to download all of the schematics. Took some effort to track down the $100 replacement relay, the suspected point of failure. Hope to have it by Tuesday the 5th.

Thanks for all of the feedback.

Hermes2 · 08-01-2022, 03:46 PM

OP here. Quick follow-up. Took the RV to well-qualified RV repair shop. Tech spent most of the day tracing wires and couldn't find a fault. However, after he buttoned it all up, everything worked again! Mystery! Suspect a bad ground that was fixed when the tech re-tightened the connections. Because they couldn't pinpoint the problem, the shop only charged me for one hour, bless them. I bought them some beer anyway. Just back from 2,300 mile, three-week trip with no problems.

Hermes2 · 08-09-2022, 11:33 AM

OP here. Final follow-up! Had the same "no 12 VDC throughout coach" issue come up a few days ago. ARRGGGHHHHH!

Again tested all circuits at the battery and disconnects. All good. Came to realize that if there's no 12 VDC through batteries OR through shore/generator power, then there MUST be an issue with converter or its connections. Again, most likely a bad ground. Checked the connections and grounds to/from the converter to the 12 VDC breaker panel and found one loose ground wire. Tightened it 1/2 turn and everything worked!

Problem solved. Not cheaply -- nearly $300 in parts and diagnosis work, plus a lot of my own time poring over diagrams and reviewing all of the related posts on this forum. I've learned a lot in the process.

Still, falling back on my old Navy BEE training from 50 years ago -- "check the simple stuff first" -- is usually the thing to do.