Battery Isolator does not seem to be working?

[Texci77]

Hello, just picked up a 2021 Seneca 37k and have noticed that when dry camping, both the chassis and house batteries seem to be draining "together" and their voltage is almost identical. It seems the battery isolator isnt decoupling the house from chassis batteries. Does anyone know where the isolator is located to troubleshoot?

[Gunfighter]

On my 2018.5 its in the compartment with the battery tray on the right side as you face the coach. I read on this site yesterday that in newer models there is a box in the next compartment past the batteries there is a wooden box that Jayco has place several of the fuses and the BIM. Are you checking the "drain" on the batteries with a voltmeter?

[Texci77]

I take a picture when I can. I dont have the battery box like the other post indicated, all the fuses relays etc are in with the battery trays as well. Was going off the voltage indicated on the touchscreen control panel. I can check with voltmeter to confirm.

[Gunfighter]

Originally Posted by Texci77

I take a picture when I can. I dont have the battery box like the other post indicated, all the fuses relays etc are in with the battery trays as well. Was going off the voltage indicated on the touchscreen control panel. I can check with voltmeter to confirm.

Precision Circuits has been phasing out the model they put in my RV. Here is a link to their page showing various models of the BIM. I believe they are installing the 225 AMPS model in newer Senecas.
https://www.precisioncircuitsinc.com...nect-225-amps/

[Texci77]

Here’s the pics, hard to tell is this is working or not. I assume once the key is in the off position it should disengage. Should be able to checks volts On both terminal posts I guess??

[Gunfighter]

There are lots of people who are a lot smarter then me on this site, but I would start simply by starting the rig and at the battery tray test the voltage for your chassis side and coach side. Once at full charge I would shut off the rig and check your voltage of both sides. You should see similar voltage (unless your coach batteries are already weak). 12.6v at rest if fully charged. If you have all electric rig your reffer should start slowly drawing down the voltage on the coach side. Alternative is to turn on your inside lights and assuming your microwave can operate thru your inverter heat up a cup of water. Check your coach versus your chassis. Are they drawing down equally or are you seeing coach drawing down faster. Repeat the microwave. You shouldn't hurt anything as long as you stay above 12.00v. If really equally drawing down then I'm wondering if your dash relay that will "bridge" your chassis to the coach is somedhow stuck?

[Texci77]

Definitely draining both. Have a load ion the inverter and house batteries are at 12.15 and chassis batteries are at 12.38. Started the engine and drove around before testing so the batteries were both holding a decent charge and started around 12.7 then slowly drained. Not sure what’s going on but something isn’t disconnecting like it should.

[Gunfighter]

Originally Posted by Texci77

Definitely draining both. Have a load ion the inverter and house batteries are at 12.15 and chassis batteries are at 12.38. Started the engine and drove around before testing so the batteries were both holding a decent charge and started around 12.7 then slowly drained. Not sure what’s going on but something isn’t disconnecting like it should.

It sounds like you do have a bad BIM. At Precisions website there is a troubleshooting guide for the older model but I have not seen one for your new model of the 225. I had good luck communicating with there tech department and you may want to reach out to see if there is any test you cann do to confirm its locked open. tech@precisioncircuitsinc.com
Also a tech telephone number on their website. Good luck. Sorry I couldn't be more help.

[Texci77]

Appreciate the responses and the help. At least I’m pointed in the right direction.

[Texci77]

Funny thing too is both seem to be charging the same ie voltage is almost the same on both banks. Going to trace out the wires better tomorrow to see where everything goes.

[Texci77]

It seems as though I "fixed" the issue. Pressed the under dash button a few times with a load on the battery and you could hear the bim open and close. Seems it may have been stuck or something because now its working as it should. Can have the microwave running and house batteries drop but chassis batteries stay up. Will still be contacting Precision circuits to see if this is a bad BIM or not. Thanks again for the help

[Rustynuts]

Originally Posted by Texci77

It seems as though I "fixed" the issue. Pressed the under dash button a few times with a load on the battery and you could hear the bim open and close. Seems it may have been stuck or something because now its working as it should. Can have the microwave running and house batteries drop but chassis batteries stay up. Will still be contacting Precision circuits to see if this is a bad BIM or not. Thanks again for the help

The disconnect can stick if the shut off switch by the entry door is pressed to long, just a quick press and release is all it needs.

[Texci77]

Thanks, have only had it for about 6 days now so working out all the kinks, seems to be working as designed now.

[thenne1713]

Either a BOOST toggle/ rocker switch defective, or (most likely) bad solenoid/ relay w/ welded contacts? Or a bad controller sending signal to close solenoid contacts?