Ground Straps

[bobbys9350]

Hi guys, im putting in my new shortblock and just have a quick question about where the ground straps go... i know the one bolts to the bellhousing from the firewall but where do the other two go? thanks a lot!

 

[jrichker]

1.) The main power ground is from engine block to battery: it is
the power ground for the starter & alternator.

2.) The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects. The best
place for the block ground is where the battery ground for the
starter bolts down. The 3G has a 130 amp capacity, so you
wire the power side with 4 gauge wire. It stands to reason that the
ground side handles just a much current, so it needs to be 4
gauge too.

The chassis ground and battery pigtail ground go to the bolt being
pointed at in the following photo.

Picture courtesy timewarped1972

Avoid using the timing cover bolts for a ground since they tend to corrode. Any other place is fine to use as a ground.

The main thing about engine grounds is that the metal they bolt to should be clean & shiny. A little emery cloth will help in that department. The same is true of the other end that bolts to the chassis. Once the grounds are connected, you might want to use some dieelectric grease on them to help keep out mositure. I don't do it, but if you live in a very wet area, it may help some.

 

[Fett]

When I redid my grounds, I replaced my ground strap with a 4 gauge wire, and added another ground of 4 gauge. One ground I have bolted to the back of the LH head, going to the firewall. Then I put a strap from the bottom of the sway bar bracket bolt (frame) to the block itself. My batter ground goes from the battery to the AC bracket bolt.

Are these not good enough locations? I still have an issue with my temp gauge moving when the lights are turned on, and the engine surges when I turn on my AC.

 

[jrichker]

When I redid my grounds, I replaced my ground strap with a 4 gauge wire, and added another ground of 4 gauge. One ground I have bolted to the back of the LH head, going to the firewall. Then I put a strap from the bottom of the sway bar bracket bolt (frame) to the block itself. My batter ground goes from the battery to the AC bracket bolt.

Are these not good enough locations? I still have an issue with my temp gauge moving when the lights are turned on, and the engine surges when I turn on my AC.

See my previous post. Clean & shiny on both ends and avoid the timing cover and you will be good to go.

 

[bobbys9350]

THANKS A LOT!