Chassis Voltage/ Over & Under Voltage Issues

[0533]

I am sure glad that I did not learn to fly this way. Although I did have a few experiences that were almost the same.

[Coloradobus]

A bad cell in one of the chassis batteries can wreak havoc, where nothing makes sense. Bruce, since you have 24 relays that make your brake lights come on with the jake, pull it and see what happens, also, try pulling the jake brake relay, as well.
I suspect though, as Prevost, its in your toad wiring harness.

that my 2 cents

[0533]

Its worth twice that much at least. Thanks Jim, I will be climbing on this problem in the morning.

You have a Marathon, could you also direct me to the so called Jump Start Relay Solenoid, what does it look like? It is supposed to be above the chassis batteries along the top of the inside Door??? I was going to test this as well.

[Jon Wehrenberg]

Bruce......please disconnect that alternator and chassis battery cable from the isolator and hook them together. If the voltage does not go down with Gen power or shore power working we can start presuming it is an isolator problem on the low votage issue. If the jump start relay was closed the chassis batteries would be seeing house battery current.

[0533]

I have made a list for tomorrow and this test is on top of the list. I plan to do a complete check list of testings.

[Coloradobus]

Bruce, I will have to look in our battery bay in the morning as well., curbside behind the tag. Our chassis batteries are not located where yours are. We have an "H".

[0533]

Good point, Have you ever noticed the Jump Start Relay before?? I am drawing a blank on the location and what the Solenoid looks like

[Coloradobus]

Bruce,

Yesterday , rolled the toll window down, reached in and hit the jump button, resulting its clunking sound somewhere at the backend of the coach. If its in the engine compartment, we can't open the rear hood with the bus inside. Can't pull it out because of a snow pile we are waiting to melt.
Good luck. Have you called Leon at Camp Marathon?

[0533]

Nice low tech way to do this, will follow suit on this one. Marathon thinks the solenoid on the relay is stuck on. I have been tied up and meetings for the past two days plan on going over this afternoon and getting to the bottom of this.

[Jon Wehrenberg]

If the relay is stuck on the chassis batteries and the house batteries should read the same, unless the relay disconnects the chassis batteries from the bus starting system, and switches starting system voltage to the house.

I doubt that but go for it. Two minutes connecting the alternator and chassis terminals will give you a bunch of information.

Got my neck stuck out again.