Engine ground to frame to battery

[achampagne]

today I relocated my battery from the engine bay to up Under the bed. Main reason was to clean up engine bay. When the battery was under the hood, the negative cable of the battery was connected to both the frame and the engine. Now, if I wanted to do the same for the relocated battery, I would have to buy a really long negative cable to run from the bed all the way back to the engine. Battery cable is expensive. So I was thinking of having one short cable ground the battery to the frame, and then another cable in the engine bay ground the engine to the frame as well. Would this be ok, or would this be a bad way to ground everything?

 

[alwaysFlOoReD]

Should be fine.

 

[RobbieD]

That would work, but try checking with a welding supply store for a lower cost on the cable, then just crimp or solder the eyelet terminal ends onto it.

 

[Josh B]

Does a ground really need to be so big? I was thinking like an old booster cable or even less, but I am not an electrician

 

[ericbphoto]

Does a ground really need to be so big? I was thinking like an old booster cable or even less, but I am not an electrician

Depends on the circuits it serves. The ground carries the same current as the power wire in a circuit. It is equally as important.

 

[oldgeek]

The longer the length the more resistance. And electrons flow negative to positive.

 

[franklin2]

Does a ground really need to be so big? I was thinking like an old booster cable or even less, but I am not an electrician

The current draw in a circuit is the same anywhere in the circuit. It's not like the starter "uses up" the power and then the ground can be smaller. The same large current in the positive wire from the battery is also found in the negative wire, so the negative needs to be the same size as the positive wire.

 

[franklin2]

And electrons flow negative to positive.

Don't get too hung up on this fact. It really means nothing in the automotive world, and can be very confusing, since most diagrams are written with their logic going from + to minus. All you have to do is look at any diagram, the fuse box is positive, all the diagrams start out at the fuse box and the logic in the diagram flows down to the negative or ground.

 

[ericbphoto]

The current draw in a circuit is the same anywhere in the circuit.

The current draw in a SERIES circuit is the same anywhere in the circuit.

 

[RobbieD]

A frame rail will work for the main ground for the engine and its starter (which is typically the highest draw on the electrical system). BUT, I would suggest making sure that the ground path is through a single piece of steel frame. In other words, don't use a path that goes through pieces which are riveted together. Such a join may be a weak point for a high-current flow, especially with some age and corrosion.

And electrons flow negative to positive.

Technically correct, but two theories are are actually used-
Conventional Theory electrons flow positive to negative
and
Electron Theory electrons flow negative to positive.

The conventional theory is more convenient to use in automotive applications, whereas the electron theory is more technically accurate, and is used in a lot of other fields of electronics.

For the electrical systems in these trucks, just use the conventional theory (current flow starts from the battery positive terminal and has to end at the battery negative terminal), and forget about the electron theory. It works, and it's so much easier.

Besides, back when these old trucks were built, that IS how electricity worked.

.

 

[oldgeek]

back when these old trucks were built, that IS how electricity worked.

Older vehicles had a positive ground.

Electrons only flow one direction in a DC circuit.

 

[franklin2]

The current draw in a SERIES circuit is the same anywhere in the circuit.

True.

 

[oldgeek]

The current draw in a SERIES circuit is the same anywhere in the circuit.

I think this is about electricity, not baseball.

 

[lil_Blue_Ford]

I’m a big advocate for better grounds. After frying an amp years ago with a poor ground, I got serious about grounds. I also had a problem on the choptop that turned out to be a bad main battery ground, the wire corroded inside the insulation to junk. Between those, I made some big changes to my habits.

I replace battery wires with welding cable. It’s generally cheaper by the foot than battery cable and it’s a finer strand which allows better current flow. I clean ground spots, add extra grounds, I’ll run amp grounds straight back to the battery, upgrade alternators and run additional wire there, etc. I use dielectric grease and No-Alox on connections. Makes a difference. My F-150 that has been upgraded has been able to jump start vehicles with no battery before. It will also run a plow pump without dimming the headlights, which was a problem prior to my upgrades.

 

[lil_Blue_Ford]

I think this is about electricity, not baseball.

Your two basic circuits are either Series (linear, electricity travels through each component consecutively) or Parallel (electricity travels through each component individually).

That said, I also get where you were trying to take that joke. But, like a pop fly to Clemente back in the day, you’re out.