Electrical Problem

Okay, so now that I'm on a 34hr reset...how do I know which is the ground? Red or black cables? It looks to me that the black cable connects to the frame...but the point at which it looks like it connects to the frame is spray painted red (it's kinda hard to see with all the wires looking like spaghetti under there)...I'm not one for wanting to see sparks so I thought I'd inquire before poking around with a wrench to tighten stuff...if I want to tighten the livewire as well as the ground wire I know I don't want to have the wrench on the livewire bolt and have the wrench accidentally touch the frame...therefore I wanna make sure I disconnect the ground first...obviously.

 

Since electrons come out of the negative side of battery, travel through circuitry, and go to the positive, I wanted to inquire about the wiring and why red was sprayed on the black ground post on the frame.

I have to admit that I have little trust in the nature of mechanics; this is since ¾ or more of my dealings with auto and/or diesel mechanics has been a mechanic not wanting to address an issue or not resolving an issue. Just last month I had two company mechanics not want to resolve a 15+ psi/minute airleak on one of the suspension airbags claiming that "as long as the truck is building air as you are driving then we can't be ordering and throwing parts at the truck." That's just one of numerous personal examples.

Yeah, I do realize messing with the electric parts near the battery is playing with one's life...jump starting someone's car in a parking lot is also playing with one's life, and I'd still do it to help someone out. The risk is known and not taken lightly. Thank you for this concern.