Community Forums

Lonnie & Bona · 05-27-2023, 04:28 PM

I am in the process of switching my house batteries over to Lithium on my 2002 Mountain Aire on a Spartan chassis. I have owned the Mountain Aire now for 3 months. Can someone please tell me where my solenoid is located so I can disable the solenoid so my house batteries will no longer be charged by the alternator? What wire(s) do I disconnect from the solenoid to achieve this. I have been researching this with no results. My wife and I are planning to do much boondocking. Can someone please helps me with this! Thanks

Lonnie
2002 Mountain Aire

DustyDriver · 05-27-2023, 05:06 PM

Hey Lonnie. I'm not familiar with your rv, but on a 2010 Fleetwood (Workhorse chassis), the battery isolator solenoid that connects the chassis and coach busbars is in the Battery Control Center. On mine it's in the electrical bay. Some folks have their BCC under the hood in the engine bay. If yours is like mine, the relay will be in that black box BEHIND the circuit board. If you truly want to disable it, there are two small wires that connect to the solenoid. Disconnecting one (or both) of those wires will keep the solenoid from closing and interlinking the busbars. Keep in mind, though, that by doing this the chassis battery will not receive any charge while you're hooked up to shore power or while running your generator. Your auxiliary start button on the dash will also become useless to you.

Good luck! Let us know where you found it.

DD

twinboat · 05-27-2023, 05:20 PM

If you have a boost or aux start switch on the dash, have someone cycle it on and off as you trace down the sound. That will be the solenoid your looking for.

mahdi · 05-27-2023, 09:41 PM

Mine is in the shore power cable bay.

Lonnie & Bona · 05-28-2023, 07:18 AM

Many thanks for the tip!! It kept me from additional crawling over and under the engine in trying to trace the wires from the batteries. In the answer to your question, my solenoid for the coach is located in the electrical bay in the rear of the Mountain Aire on the driver side. Additional questions to your response.... I want to disconnect the house batteries from the alternator but still maintain charging ability from shore power and generator to the house (Lithium) batteries I am about to install. My Trace converter/inverter electrical diagram shows there is a islolator situated between the alternator and the house & chassis batteries to keep the two battery banks separated. Would it be better if I disconnected the house batteries from the isolator so I can discontinue charging from the alternator, but still maintain the ability to charge the house (Lithium) batteries from shore/generator power? I would leave the solenoid to the house batteries wired as it currently is. Thanks for any additional advise you may have!

twinboat · 05-28-2023, 08:11 AM

The solenoid is simply a switchable jumper between the batteries.

The alternator is connected to the chassis batteries and the inverter/charger is connected to the house batteries.

Disable the solenoid by removing 1 small wire and your seperated.

Gaetan Lavoie · 05-30-2023, 06:44 AM

Lonnie,

What has been suggested will disable the solenoid but will deprive you of recharging the Lithium batteries when travelling on the road which maybe acceptable or not depending on your situation.

There is another option which you should look at and it is replacing that solenoid and BIRD arrangement with the LI-BIM 225. See the enclosed attachment for more information.

When my solenoid failed, I replaced the Solenoid BIRD arrangement with the BD-225 designed for conventional batteries as seen below. This was fairly easy to do and I am pleased with the results.