H3 40 Liberty 12 volt master

[Judi Brown]

We find that the light is staying on for the 12 volt master even when shut off.
We think that it was off before and notice bus batteries low. Is there way to check and is it suppose to be off . Turn 24 volt off and the light goes out.
Thanks. Judi

[Jon Wehrenberg]

Judy,

May we assume the light you are talking about is at the lower RH side of the dash panel that has the depiction of a bus?

If so, are you turning off the silver knob in the rear near the 24V master for the chassis? The chassis has two shutoffs, the large one for 24V and the smaller (same size as house shutoffs) for the 12V for the engine computer.

If you are turning it off, access the rear of the switch and check for continuity with it ON and an open circuit with it OFF.

[Judi Brown]

Hi Jon, Thats the one Iam talking about. We shut 24 volt off and light goes out. We shut 12 volt off and light stays on. When he turns house switch in motor compartment off, it goes out but other lights don't work . He tried to start coach with 12 volt in off, thinking if switch was staying on bus would start.
But didn't. We are not sure if it was on all the time before, didn't notice.
Our only concern is if our bus start batteries will go dead , with it being on.
Judi

[Jon Wehrenberg]

I haven't looked at wiring diagrams from your vintage and shell, but as we have found out even with the chassis battery switches OFF (both the 24V and 12V) it is possible for the chassis batteries to go dead. That is dependent upon where Prevost chose to connect for power to the DDEC computer, either before the disconnect switches, or after.

Assume they will drain, and monitor their voltage until you know for sure one way or the other. There does not appear to be a single answer to this question.