Yep, that's what I was planning on doing when I was doing it myself. But my installer guy found a bolt under the rim of the Stow-n-Go seat storage compartments and I figured it was a good ground, so we used it. I'm gonna get some jumper cables Tues (to run a test ground) and a new VOM (my old one is only a VM now!) but I can imagine we will be running a 0AWG ground cable off the battery as I had originally planned.
How do you resistance test ground points???
Test the resistance between a suspect ground against a known good ground like the car battery neg terminal post. Ideally there should be no (zero Ohms) resistance between the two electrically. And at the other extreme, infinite resistance (no continuity) it means the two are not electrically connected at all. I Googled "testing automotive grounds" and evidently from what I read more than 3 or 4 Ohms resistance between them means not a very good ground. I would shoot for ZERO Ohms difference myself. Which is probably what we (my installer guy and I) will end up doing. Just run a dedicated 0AWG ground cable from the battery neg post. The 12V+ we have is directly from the pos battery post. That's the best ground I could get!
Ideally there should be NO electrical difference (0 Ohm resistance) between the alternator case and the neg battery terminal. So the neg battery post SHOULD be as good a ground as the alternator case. Why don't we run a 12V+ from the alternator pos side? Again, ideally there SHOULD be no electrical difference!
Depending on WHEN!! Upon starting the vehicle ALL the electrical power/current/etc. is coming from the battery. That's the battery's job, starting the car. After starting and once the alternator comes up to full function then the alternator powers everything electrical in the car, including keeping the battery (hopefully) fully charged for the next "starting" necessity.
Thanks. i thought tool may have a different answer.
You are correct. For simple continuity testing it's tested with a very small voltage and current test. Tells you nothing of how much current the circuit could safely accommodate. And yes measuring voltage drop under a known load will tell you a lot about load ability. If the voltage drop is significant under a relatively light load then you know you're in trouble.
Yep, my installer guy emailed me and said it would be best to have both wires as identical as possible and that means KnuKoncepts (sp?) 0AWG just like the 12v+. I told him to order some. He bought the $129 install kit in the first place, so he's conversant in ordering the correct stuff.
