mtyson

Thanks for the encouragement!

I'm still generating more questions than answers in my mind, but eventually those will resolve out into understanding...

Just one question on grounds.. .since electricity flows from positive to negative, are the grounds there to provide a path for any errant electricity from the system, and/or generated by the environment/movement etc?

BlueRidgeMark

Grounds are there to provide the complete circuit to the battery. Every electrical circuit goes from the power source (battery in this case) to the load, and back.

Using the body/frame of a vehicle allows us to complete the circuit without having to run wires both ways to every electrical load.

Take the rear lights, for example. We could connect them to the battery (through various switches, of course) by running two complete wires to them; one from the positive terminal, and one from the negative terminal. Multiply that by every light, every motor, every everything that takes electricity, and you see that's a lot of copper and labor. But all that nice convenient conductive steel is already there! We just borrow it to run the other side of the circuit. That's all.

As for "errant electricity from the system, and/or generated by the environment/movement etc", there is one ground wire that does that. It's the braided strap that goes from your head.. no, not your head, the Jeep's head... to the firewall. It's to short circuit any stray current generated by the switching of the injectors, which might otherwise translate into noise in your radio.

mtyson

OK, I think I am making a connection here, and this will probably sound dumb as heck...

The ground wire that goes from the passenger fender to the negative battery... that is to bring the current from the chassis back into the battery? I have always thought it was so extra charge could dissipate from the battery/electrical system into the chassis and down to the ground...

I'm pretty sure I sound like an idiot right now...

(I better go read up on 12volt.com some more.)

That explanation helped a lot, thanks BRM.

BlueRidgeMark

Exactly!

And the ground wire to the block provides another path for that. The fender ground wire isn't big enough to handle the current that the starter draws, so we provide a bigger cable for that.


And no, you don't sound like an idiot, you sound like someone who has not yet learned about electricity. That puts you in good company with most of the planet!

mtyson

Thanks man, its actually starting to make sense!

Some

LACK

Not a dumb question at all. Ask away, there is only one way to learn. Electrical intimidates a lot of people.


There is also another ground that goes from the firewall on the driver side to the head.

5-Speed

Mtyson - You seem to be catching on fast. There are a lot of electrical gurus on here so whenever you have a question, even if it seems like a dumb one, ask it. Most people are on here to help you learn, not make fun of you for something that you ask.

BlueRidgeMark

Yep. That's the one I mentioned for radio noise suppression. One of the guys that sells battery cable upgrades sells a massive (4 gauge, I think) cable to replace that. Don't do it. That braided cable is the right thing for that job.


Agreed!