what is the ground wire from the back of the engine to the firewall for

and can can i run it anywhere else besides to the spot on the firewall that it was originally in?

 

As you stated, it’s a ground wire.

 

yes, i know that..... but I'm asking what does it go to and can i run it anywhere besides to the firewall?

 

see..... i broke the screw that mounts to the firewall, and i need to mount it somewhere else

 

Mount it anywhere on the firewall that will ground

 

okay thanks HondaGM

 

If your ground wires are not up to speed you can have lots of problems,
Anywhere on the fire wall is ok,
But wire brush the paint off the firewall spot so there is a good ground contact.
You might want to upgrade that ground wire to a thicker gauge too.

1) The body should be grounded, one wire from the firewall to the engine,
One from the battery to the fender.
2) ground wire from battery to the engine block
3) ground wire from engine block to the frame and then to the negative side of battery.

this way all three parts of the truck (body-frame-engine) are guaranteed to be grounded .

 

Every Toyota I ever bought I never had one of those wires in place .

Engine is pulled it never is replaced.

Something to provide protection on the line when being built?

What it does I have no idea mine were never replaced seems to be a extra ground to small to handle much of a load .

Between all the vehicles a million miles plus.

 

It’s a redundant ground. It won’t hurt to have it gone. But it doesn’t hurt to keep it around. The most important one is the one at the bottom of the block with the large wire. The other one is just there.


Can speak from experience with the mr2. If you don’t have a generous ground wire or multiple grounds; the starter won’t be able to get enough current to start…

 

Thank You Sir!!

I always upgrade my Ground cables run an extra to the frame to give a good frame ground at the rear for trailer brakes and lights.

Assorted others over the years starter bolts and ECM connections.

 

Yea I tend to beef up the main big one. I will leave the smaller one on the firewall alone. The smaller one technically is there to give the injectors, sensors and coils a shorter path to chassis ground, but never seen an issue with it gone

 

Yeah as these age and corrode....trusting a round-about body ground seams as smart as keeping 20yr old vacuum lines.......

I run a braided cable direct off neg post straight to computer mount on intake plenum....

There's a lot firing off that harness, 40a AM1, and 30a AM2.......
you dont want em thrusty do you.....

Bad grounds love to fry circuit boards........if you want to find out.....go cut the common going into your house and operate your appliances for a week.....
see which ones survive......

 

... How did you break it? I have extractor sets on hand, so if I were in that position, I would go try to remove the broken bolt, and continue to use the original setup. Adding additional wire to relocate that ground that elsewhere just sounds like a future nightmare.