Weird electrical (1 Viewer)

[Varty Yo]

Ok so im wiring up my EGT anf running the ground directly to the battery as told. My issue is i ran it to the neg on the driver side battery but it wont ground off of it. I touch the wire to the passenger side battery and all is well. Seems wierd to me im kinda stumped.

P.S i hate all electrical work.

 

[remy]

the batteries are connected in serie. So only 1 bettery is connected to ground, most likely passenger side on a BJ42. The negative terminal of the driver side battery is connected to the positive of the passenger battery, and so 12V

 

[Varty Yo]

Kinda what i was thinking in my head! haha. Good to know ill proceed with install