B2 Carson .... transformer ???? And where to Ground ????

[KZGoodchild]

Hi all, I took out this little heavy square box from around the shore power area, I am not sure what it was for, it says B2 Cars, then some voltages....
I'll try to post a pic this week.... any ideas?

BTW, I have a fuse panel from VTS, and the ground or negative bus does not seem to have a connect to the battery or frame, I am thinking of using the last terminal on the bus to run some 8 ga. to the neg, and split to the frame.... good plan or not ???

Thanks for any input.
Mike

[KZGoodchild]

here is the doo hickey...

[TG Twinkie]

Looks like a 120 volt to 12 volt transformer. Used for low voltage lighting.