Ah OK now this makes a little more sense. This is the reason you are seeing the voltage you are on the dash. Which BTW is normal even with one batt due to different charging cycles.Yeah I think that’s what I’m trying to say lol. Again apologies for my total lack of knowledge on this. I put a brand new yellow top under the hood. So is that a normal thing for the voltage to be “12vdc stable” after installing the second battery?
If you had a serious issue you would have dimming headlights or even worse. That said see the next paragraph below.
Hey I did some of that new fancy photo filtering of this pic because I wanted to see if that was a clamp around the black negative wire on your car. Lol I am old fashioned haaa.
Can you take a more clear pic of the area in the pic? I think that is a clamp around that cable.