Intermittent 12v chassis power loss

[RV Lifer]

Good day,

First time posting on the forum from which I've learned tons in the year and a half we've owned our 2007 Winnebago Journey 34H with 350 Cat.

I'm experiencing an intermittent full loss of all 12v chassis power to the unit. Either I haven't any power to even display anything when turning on the ignition and no electric power to driver's seat and headlights or we have power and am able to start it then put it in gear and drive a few yards to then have it completely shut down the engine and all 12v power.

Troubleshooting I note that when no power, I have no voltage readings at either side of the first bus fuse after the battery. All battery terminals have been cleaned as well as the ground to chassis. The batteries have been load tested and are in good shape and reading 13.4 volts.

I'm thinking I have something heating up pretty quick and shutting everything down. I'll then have power the next morning!

Looking for some insight on where to explore further this issue.

Thanking you in advance.

RVLifer
2007 Winnebago Journey 34H, Cat 350

[ThomB]

I'm no expert in wiring but I know enough. I was going to say you have a ground problem but it looks like you have already addressed that.

Does your coach have a battery disconnect solenoid? Could that (or a component near to there) be on the fritz causing your issues?

[RV Lifer]

Originally Posted by ThomB

I'm no expert in wiring but I know enough. I was going to say you have a ground problem but it looks like you have already addressed that.

Does your coach have a battery disconnect solenoid? Could that (or a component near to there) be on the fritz causing your issues?

Thanks for the reply. Yes, there is a battery disconnect relay as well as an auxiliary battery boost solenoid which I considered could be the problem. I've had voltage readings on these which I assumed were from the house batteries side.

[ThomB]

Originally Posted by RV Lifer

Thanks for the reply. Yes, there is a battery disconnect relay as well as an auxiliary battery boost solenoid which I considered could be the problem. I've had voltage readings on these which I assumed were from the house batteries side.

We have a disconnect for the chassis battery that I'd be giving a closer look at (assuming that you have one of those).

[RV Lifer]

Yes, you've helped me realize that what I thought to be the chassis battery disconnect solenoid up front is in fact the house battery disconnect relay as the voltage doesn't agree with that of the chassis battery. I'm on the hunt now for where the chassis disconnect relay is located. The actual turn switch is above the rear radiator. Thanks for your help. :-)

[al1florida]

Originally Posted by RV Lifer

Yes, you've helped me realize that what I thought to be the chassis battery disconnect solenoid up front is in fact the house battery disconnect relay as the voltage doesn't agree with that of the chassis battery. I'm on the hunt now for where the chassis disconnect relay is located. The actual turn switch is above the rear radiator. Thanks for your help. :-)

I think the big chassis disconnect switch in the engine compartment is the mechanical disconnect. That is I don't think you have a disconnect relay (solenoid) for the chassis battery.

Here is a link to wiring diagrams for Winnebago motorhomes: Wiring Diagrams

[RV Lifer]

Thanks again for takin time to reply. I have previously downloaded all available manuals and diagrams from Winnebago however, they don't contain chassis specific details. As you correctly noted, there's no solenoid / relay. So, just wondering how reliable are the mechanical switches? Also, since I haven't any diagrams for the chassis wiring, I don't know if there's anything else before or after this switch and before the first buss fuse. When I lose power, there's no voltage at the first fuse.

[RV Lifer]

As a final update, the chassis battery disconnect switch was the culprit. In my model, it is installed outside above the rear radiator and subject to the elements as there is a vent at the bottom of the switch. I found that both terminals were corroded and one terminal was loose within the switch. As a temporary fix, I connected both in and outbound lines together on the good terminal to bypass the switch.

[ThomB]

Good find!

[fchuck]

Have 2002 Brave 30 with major “Reduced Engine Power” issues. Can you send link to wiring diagrams? We think it’s electrical problem. Thx