Engine ground

[kaisermusic]

Hey,

how is the engine normally grounded? I just finished running all new wiring and want to run a new secure ground from the body to the frame and the engine to the body.

Thanks!

 

[Viperwolf1]

Engine should have a cable going directly to the battery negative post. Engine is where the largest current is used. The body should have a heavy ground strap going to the engine. The frame doesn't really need a ground strap unless you have added ground points to it from a winch or fuel pump or something.

 

[kaisermusic]

ok, where should i tie the body ground to the engine at?

 

[Viperwolf1]

ok, where should i tie the body ground to the engine at?

Firewall is a good place. You could run it to the engine at the intake manifold or back of the head.

 

[DirtDonk]

And when you run the main large cable to the engine, don't scrimp on the length. Better to get the cable mount bolted to the block as close to the starter motor (point of largest use) as possible.
Somewhere between the alternator and the starter is typically where Ford put them. On later model engines (don't know how far back it goes) there is a blank 7/16 threaded hole just in front of the starter on the oil pan rail area. This is perfect for an engine ground I think!
I'll bolt them in, but also now have a supply of 7/16 x 14 2" long studs that I keep in my electrical box just for this reason.

And make sure your new battery negative cable has an extra wire that you can tie into the body directly. Yes, the ground strap from the engine will do this pretty well, but the one straight from the battery is a nice addition (and was there originally anyway) and can help things forward of the firewall, such as the front lights and horns and such.

Can't have too many grounds.

Paul

 

[Teal68]

Anybody got a pic of where the ground strap attaches to the firewall?

 

[jckkys]

A great source of grounding straps that are OE Ford parts is police cars. They ground everything including hood and trunk lid to avoid two way radio interference.

 

[DirtDonk]

There are no specific spots specified by the factory. It's up to the individual since Ford never put a ground strap between the firewall and engine of an EB. They'd already been doing it on other vehicles, but I've yet to see an Early Bronco that had one from the factory.

Here's one I did with a friend. See the bolt on the left with the ring terminal under it? That's the end of a strap going down to one of the manifold bolts.



We removed the paint underneath, but after it's all done will paint over the bare spots with the wire(s) in place.
I've also ground a spot bare, and put a bolt in from the other side with a nut, basically to act as a stud for adding ground(s) and wire loom clamps.

In the case of the EFI intakes, some of the bolts come complete with their own stud which is a perfect place to put the ground strap. I don't like putting it under an intake attaching bolt unless you can do it before the first time you torque it down. If you do it after the fact, it can promote a leak in that area.

I know plenty of people who've loosened one bolt and added a ground strap and never had a problem. But I also know plenty that have done it only to have a coolant or vacuum leak as the result.
It's ultimately up to you, but if you don't want to chance it, there are probably some extra threaded holes somewhere on the intake that you can use.

Paul

 

[ransil]

I weld a stud in the wheel well near the battery and also weld one to the frame either in the motor mount bracket or the frame near the spring tower.

 

[Teal68]

Thanks guys.

The reason I was asking is when I pulled the motor out of the 68 there was a grounding strap, but for the life of me I can't figure out where it attached. I can't even find evidence of it anywhere. It's a nice flat one with coating over it.

Is there another place that is more common?

 

[Steve83]

Typically, the battery-to-block cable attaches at a starter bolt (between the bolt head & the starter mounting eye) or to an engine mount bolt/stud. It doesn't hurt to add one the same size as the alt. output wire from the battery (-) to a clean spot on the alt. case. To add a body ground, pull a body ground stud (easy to spot because they're green) from a later truck ('92-96) and screw it through several layers of inner fender/core support. That will ground the entire tub since an eB is welded continuously from the core support to the t/g threshhold.



On Frank's '75, I used an '88 F150's wiring, so that ground cable had the tab for the frame, and I added a stud forward of the R spring tower in case he ever added a winch, bumper lights, or other frame-grounded accessories.

 

[Teal68]

Thanks Steve. Great suggestions! What is striking me as odd is that I pulled this ground strap off when I pulled the motor, and can't remember where it was. Anyhow, lots of options to accomplish the same thing.