[Fulltiming]

I will go check, but I don't think my 1992 has a separate isolator.

[Chester Stone]

Chappell, you are correct and Michael explains why the switch is an on-off-on switch. When plugged into outside power, turning the solenoid on charges all batteries with the inverter/charger, and in an emergency, toggle the switch to start the engine and/or generator. If there is no isolator, then I do not see how the alternator can charge the house batteries except through the inverter/charger. As to installing an isolator on a coach that does not have one, I would have to do considerable research to be sure I installed it correctly.

[Flick]

Do I simply turn the battery kill switches off to change that or do I disconnect all if the batteries?

[Retro]

Maybe mine charges through the inverter charger? Ill have to check, I have never had a charging issue, but curious how it all works and this will be a great thread for future reference.

[Fulltiming]

I just verified that my 1992 does NOT have a separate isolator. Checking the Owners Manual confirms my earlier statement that, at least on my 1992,:

"A solenoid automatically merges the two 12 volt systems when the ignition key is on except while operating the starter. Therefore, both the chassis battery system and the house battery system are charged automatically from the engine alternator while the coach is driven.

The house battery system is also charged by a converter/charger located in the back of the shoreline compartment any time 120 volt power is available (generator or shoreline). To charge the chassis battery system from the converter/charger or to get extra battery power for engine starting, the two battery systems must be manually merged using a switch on the dashboard labeled "battery merge." This switch has two "on" positions, either up or down, so that it has power to function even is one battery system is dead."

1992 Newell Owner's Manual

[Retro]

This makes sense now, so when the ignition key is on the merge solonoid is energized charging both sides. When the ignition key is off or no power to the merge solonoid, the merge switch energizes the solonoid depending on what side is low is what way the switch will have to be on to get the batteries to merge when the engine is not running correct?

[Fulltiming]

Correct!!

[Retro]

So what is the isolators job then?

[Fulltiming]

Newell did not start putting in isolators until sometime after 1992. So, if you have an earlier Newell your merge solenoid is doing double duty. If you have a later model, it appears that the sole purpose of the merge relay is for manual override and the isolator handles merging the batteries when alternator power is applied.

[Flick]

What do I need to turn off or disconnect so that I don't kill myself changing this. I assume I can get it at a truck parts store right?