BIM 160 (wired right)??

[Grumpy Grampa]

2017 Thor Miramar 37.1


Hi. I checked the voltage at my BIM 160 and got over 12 volts at post A and post B on the BIM 160, when I had the chassis battery negative cable removed?

Does this means I need to switch the A and B cable at the BIM, or do I need to disconnect the positive terminal on the chassis battery, instead of the negative?

I understand I should not get 12 volts at the BiM from battery side if chassis battery is disconnected.

Thoughts.

Thank you

Thank you

 

[Chateau_Nomad]

Have a read... wiring diagram is pretty straightforward.

https://www.thorforums.com/forums/f8/bmpro-bim-160-question-37358.html

 

[Grumpy Grampa]

Hi. Just to confirm, does it matter which chassis cable I remove, to see if I do not get power to the BIM 160, when took off the negative cable, I got 12 plus volts at both BIM 160 A and B terminal.

Thank you

 

[16ACE27]

Hi. Just to confirm, does it matter which chassis cable I remove, to see if I do not get power to the BIM 160, when took off the negative cable, I got 12 plus volts at both BIM 160 A and B terminal.

Thank you

How are you measuring voltage? Voltage is a 2 point comparison. Are you measuring terminal A to chassis ground and terminal B to chassis ground? Or are you measuring terminal A to Terminal B?

I don't even understand why you are lifting a battery lead to check BIM operation.

 

[Grumpy Grampa]

Thanks yes. A to ground and B to ground. I am trying to determine if it’s wired right. I thought if I take the positive or negative cable off the battery , I could check the BIM to see it’s wired right to A terminal with no voltage.

 

[PS89]

You need to either remove both the cables from the chassis battery or the "jumper" from the coach battery bank to completely isolate the cables at the BIM. Relying on the Thor documentation and the factory performance alone can lead to ambiguous results.

 

[Chateau_Nomad]

I don't get it. The BIM terminals are labeled. Why not just trace the cables? Or remove one and check continuity? Get the cables on the proper terminals FIRST, then check operation using voltage.

 

[Grumpy Grampa]

The cables on the BIM were reversed. So i put them on the right posts.

Thank you for all your help. I hope batteries now charge during driving to keep my refrigerator running, without my inverter giving me an error code.

 

[DavidEM]

You should see a big improvement. Before I corrected the misfired cables I would only get 5 amps or less charging current to the coach batteries from the chassis. After I switched the cables I would get 30 amps.

Thor has perpetuated this problem by showing the BIM wired incorrectly in their own schematics, at least for my 2021 Axis. It is hard to train your installers how to do it right if the textbook is wrong.

David