[James408]

Just had a question about ground straps....In my 69 Firebird 400, I have three grounds on the motor. One from the back of the right head to the frame, One from the front of the right head to the frame and one from the front of the right head to the battery. There is a ground strap from the frame to the firewall. should I put one of the ground straps from the head to the firewall. and do I need a ground strap on the left head.


thanks, the only original ground strap is the one from the frame to the firewall.

[chuckies76ta]

Just think of it like this. The ground straps are only as good as their connections. You could have 10 straps from the engine to the frame. If only 2 made a good connection, you'd only really have 2 working ground straps.

The - ground on a vehicle is the other side of the battery path for current to complete a circuit. Therefore the grounds are essential for devices to work.. The metal in the vehicle is used as a path back to the battery.

It sounds like you have enough grounds on your system.. Having said that I like running a ground from the back of the head to the firewall..

My thought are sometimes you can never have enough grounds, as electrical problems usually end up having something to do with the grounds.

Hope this is not to confusing.. Don't over think it..

Charles

[James408]

Thanks Charles, I believe I'll just move the ground from the back of the right head from the frame to the firewall since I already have the ones in the front going to the frame and battery. Thanks.

[66bonne]

Just my 2 cents, which is worth half that much. I run a ground from each head to the fire wall. I then run a ground from the block to the frame [up at the front of the motor] and another from the block to the firewall. I agree with Charles, can't have too many grounds.

Jim

[george kujanski]

Since the main battery neg connection is to the engine block, the frame, firewall, rad support should all eventually connect to the engine block for best grounding.

On an "A" body, the body (firewall, etc.) sits on rubber cushions to the frame, which is why the body and frame need separate grounds.

On modern cars with computer systems, practically each system has individual ground connections.

You can never have too many.

George

[pfilean]

Pontiacs usually had the negative battery ground to the driver side head. Also usually had a ground on the driver side from the back of the head to the fire wall. Should have a star washer under each end. That is one that assures good electrical return path from all that electrical stuff on the body like lights, radio and gauges. Then for a lot of years (every thing is a little year dependent and sometimes plant dependent) there was also a ground on the passenger side from the rear of the head to the fire wall. I suppose just to make sure as the connection of the little star washer through the paint might not be good on the driver side. Kind of a belt and suspenders idea. Then there was also often two ground straps from the inner fender panels to the frame. Maybe intended as a radio suppression function as there is really no electrical item attached directly to the frame that needs an electrical return path. But what the heck - add them anyway. And its true you can never have too many as the first mechanic or body man that encountered one left it off when he finished his work. To him they were just a nuisance.

[James408]

Thanks guys! So far now I have the following:
Back of right head: ground to firewall and ground to frame

Front of right head: ground to frame and ground to battery

Then ground strap from firewall to frame. Passenger side.

[trmjr1]

The car originally had two ground straps and the negative battery cable. The negative battery cable is grounded to the second head bolt on the passenger side bank - secured with a castle nut.

There is a ground strap from the back of the passenger side cylinder head to the firewall and a ground strap from the subframe to the body across from the oil filter housing.

Tom

[fatguyterry]

I worked as a mechanic for Pontiac from 67-84. some were between those years I recall some one or Pontiac did not ground the firewall very good and the and the auto shifter cable now became the ground. first the cable is not very thick and second when that thin cable tries to be a ground it becomes very hot and melts to the plastic casing and now you can't shift the vehl. grounds are very important and as said you need to ground the engine to frame, engine to firewall, frame to frt fender skirts (ground for ant). if grounds do not have a very good connection it's time to get the hotdogs out, because you can burn it to the ground.

[dmac]

Ground from firewall to frame is pretty much useless since ground is through the block to battery if you already have a good ground to each. Frame is grounded already, and body is grounded through the firewall ground. There is no electrical value grounding a ground to a ground- it is like adding another ground between to objects that are already grounded. If anything, ground the radiator support to the battery for a better ground to headlights, electric fan, turn signals.

Fenders may have had ground straps to frame to provide ground for fender mounted side marker lights, turn signals, etc

[James408]

Thanks guys! I appreciate yalls help!!