More Bizarre Thor Electrical

[motofabio]

2019 Thor ACE 30.2

My radio continues to inconsistently lose power, after replacing the stock Axxera with a new Pioneer. Some have said it’s a radio problem, but there’s no way different units from different manufacturers behave the same way. I replaced the new wire harness just to be sure that was good. Same issue.

Because I can run the radio while the engine is off, I know the radio runs off house batteries (this is normal). So today I thought I would connect the radio to the engine battery. First step, disconnect the engine battery. After that, the headlights still work and I can turn the engine over!

Also, earlier this year I installed a voltmeter directly to the engine battery and house batteries (separately) and it still shows power on both have power. So this means somewhere in the wiring Thor bridged the house and engine. Somewhere. What in the world?! And I living in a cuckoo clock?!

[Bob Denman]

Try turning the Use/Store switch to the "store" setting, and see what happens.
You probably have something going on with the connection between the chassis and the coach batteries.

[16ACE27]

Are yo plugged into Shore Power? If so, unplug and see what you have.

Having the systems "cross-connected" when you have a charging source is normal but I am sure cranking the engine without the chassis battery connected put a great overload on the BIRD/BIM solenoid.

[motofabio]

I unplugged from shore, disconnected engine battery, and it fired up.

[Bob Denman]

... and the Use/Store switch?

[HarryS]

Unless the device that connects the chassis and house batteries is stuck closed.

[JimOIB]

Or...somewhere in your voltmeter wiring you may have bridged the batteries in a way that makes your isolation relay/manager think the emergency start button is “pushed”.

[Campnjoe]

Is your emergency switch flipped. It allows you to start the motor with the house batteries.

[cavie]

Agree with Campenjoe. There is a switch up front that allows you to combine the two batteries for an emergency start situation, Either the switch is on or the relay that controls that function is stuck. It's not weird when you understand how it works.

[surfjakel]

I think my emergency start switch is stuck in "pushed" position as well. Anyone familiar with a quick way to disconnect this functionality to test? Fuse or cable, etc.

[HarryS]

Easy thing to do would be disconnect either the small wire positive or small wire negative from the BIRD, or whatever acts as the solenoid to connect the batteries together. It uses the small gauge wires to activate the device.