Auxiliary Battery Switch

[Kenneth Neal]

I have a 2012 Daybreak with a single disconnect battery control center. By accident I have discovered that I can start my engine when the chassis battery is disconnected without activating the auxiliary start switch on the dash board. In other words the house battery seems to always connected to the starter switch. This seems wrong. I called Thor's customer service and was told very unconvincingly that was normal. I asked if that was normal then why is there an auxiliary start switch on the dash board. The customer service rep had no answer. I need a second opinion regarding this.

In addition, when plugged into shore power, the Trombetta Isolator Solenoid gets disturbingly warm/hot which would indicate a lot of resistance in the circuit. Could a bad solenoid be part of the problem?

[Oneilkeys]

You can read the voltage of the chassis battery and the house batter(ies) from the two poles of the Trombetta. If the batteries are above 12.8v, the BIRD keeps the Trombetta open. So if the batteries are above 12.8v, the house batteries will be connected to the starting system and the engine will start using the house batter(ies) without using the aux start switch. However, when the batteries fall below 12.8v, the BIRD should tell the Trombetta to open, disconnecting the chassis battery from the house battery so the chassis battery does not discharge the house batter(ies). If the batteries are below 12.8v and you can still start the engine with the chassis battery disconnected, then either the BIRD is not telling the Trombetta to open or the Trombetta is not opening or the auxiliary start switch is miswired or locked open. Talking to the Trombetta guru, it apparently almost never fails. That seems to indicate that either the BIRD is faulty or, more likely, the system is miswired or the aux start switch is locked open.

[Kenneth Neal]

I'm not sure I'm following you. You said if the batteries are above 12.8 V the BIRD keeps the Trombetta open. Later in the paragraph it said if the voltage falls below 12.8 V the BIRD should tell the Trombetta to open. Sounds like the Trombetta is always open. When is the Trombetta closed?

[Oneilkeys]

Originally Posted by Kenneth Neal

I'm not sure I'm following you. You said if the batteries are above 12.8 V the BIRD keeps the Trombetta open. Later in the paragraph it said if the voltage falls below 12.8 V the BIRD should tell the Trombetta to open. Sounds like the Trombetta is always open. When is the Trombetta closed?

Sorry.. Senior moment. The first sentence should read the BIRD keeps the Trombetta closed... It only opens it to seperate the batteries when the voltage drops below 12.8v so that the starting battery does not draw down the house batter(ies) to the point where you do not have enough voltage using both to start the engine - if everything is working properly. My system was miswired so the BIRD never closed the Trombetta to charge the chassis battery when on shore power or generator. I don't see any way that your BIRD could be reading above 12.8v all the time so that it never opens the Trombetta and seperates the batteries. However that is easily checked by discharging both batteries below 12.8v and then checking to see if they are seperated. If they are no longer connected, running all your lights for a while will draw down your house batteries and after a while you should see a difference between the voltage on your house and chassis battery. If you do, that indicates the BIRD and Trombetta are operating properly. It seems more likely that the aux start switch is miswired or stuck in the closed position.

[Kenneth Neal]

Oneilkeys,

Thanks for your reply. I have done some testing and will be doing some more. I suspect it's a bad auxiliary switch. I'll let you know if I find the culprit.

[Oneilkeys]

Good luck. It took me a week to understand, find and fix my miswired BIRD problem.

[petef]

I have discovered the reverse situation in my 2014 Hurricane 27k, with the coach batteries disconnected I still have 12v power, ie, lights, and stuff still work. If I hit the "store" button everything goes out. It seems my chassis battery is connected inline with the coach battery on "use". if I disconnect the chassis battery from the evans box the 12v power stops ( with the coach batteries disconnected) I can't figure if this is normal or maybe the switch to coach to chassis selinoid is broke. Disconnecting the switch at the dash made no difference. it is something in the box. Any ideas? I have not try to run down the coach battery and see if anything changes, but a full disconect should read zero to the ? whatever?
Thanks

Originally Posted by Oneilkeys

Sorry.. Senior moment. The first sentence should read the BIRD keeps the Trombetta closed... It only opens it to seperate the batteries when the voltage drops below 12.8v so that the starting battery does not draw down the house batter(ies) to the point where you do not have enough voltage using both to start the engine - if everything is working properly. My system was miswired so the BIRD never closed the Trombetta to charge the chassis battery when on shore power or generator. I don't see any way that your BIRD could be reading above 12.8v all the time so that it never opens the Trombetta and seperates the batteries. However that is easily checked by discharging both batteries below 12.8v and then checking to see if they are seperated. If they are no longer connected, running all your lights for a while will draw down your house batteries and after a while you should see a difference between the voltage on your house and chassis battery. If you do, that indicates the BIRD and Trombetta are operating properly. It seems more likely that the aux start switch is miswired or stuck in the closed position.