[WHITESPRAY]

My 3200 has a Battery Interconnect Switch that was left in the On position while running both engines.  What damage can be done to the batteries or alternators when this occurs?  Tiara manuals say this should only be done when running on one engine or if a battery bank is not working?

[jclark003]

hard to say without knowing your battery and charging configuration. I would turn the switch off, and check voltage on both banks while engine running to be sure both alternators are charging. if you have low voltage with engines and charger off a battery load test will tell you if any of the batteries are below spec

I accidentally left my interconnect switch on all season and had no issues with either alternator or batteries. Both banks had the same batter type and rating.

[WHITESPRAY]

Thanks. We were running at high cruise when both engines shut down. Reset the switch correctly and both Cummins diesels ran fine.. I'm going to have a check done on both battery banks and alternators.

[jclark003]

seems strange that your engines shut down with the switch closed. I can think of no reason for that to have happened Unless both alternators failed and the batteries went flat. That would be pretty unusual and I suspect you would know that happened at this point in time. Good move getting the system checked out to be sure.

[WHITESPRAY]

seems strange that your engines shut down with the switch closed. I can think of no reason for that to have happened Unless both alternators failed and the batteries went flat. That would be pretty unusual and I suspect you would know that happened at this point in time. Good move getting the system checked out to be sure.

My only thought is the ECM's sensed a serious electrical problem and shutdown. But I never got trouble code on the Cummins monitoring system so that's unusual. Engines immediately started up after we reset the switches properly. I'll keep you posted.

[WHITESPRAY]

Check of the Electrical System showed the Regulator in the Stbd Alternator had failed. Might be unique to the AC Delco alternator with built in Regulator. Would still like confirmation from someone at Tiara.

[jclark003]

My last two diesel powered tiaras, and most of the ones my friends have, all use external regulation. I wasn't aware they put internally regulated alternators on any of their diesel rigs but for sure I am no expert.

A failed regulator could certainly be the result of two alternators running in parallel. there are special regulators and blocking diodes that are designed to allow for this. An internal delco regulator is probably not.