Grounding questions

[younggun2.0]

I am getting ready to rewire my entire car. I want to know what everyone is using for grounding there cars. I currently have my battery mounted in the trunk. i have 1/0 cable going from the battery negative terminal straight thru the floor and grounded to the rear frame rail. On the engine, driverside front cylinder head i have a 1/0 flat braided strap going to the driver inner fender where the factory battery would have grounded. what else do i need guys?

 

[Bad Sport]

Most cars from the factory also had the braided ground from the rear of the passenger head to firewall.

 

[memike]

Another would be from the negative side of the battery to the radiator support.

 

[crackedback]

Run a remote ground post. If you are going to use the factory metal to run a ground, use the frame rails, especially if you have frame connectors.

Car have a roll bar with bars going into the trunk? Run a ground from the battery to bar, then have a post up front off your bar for grounds to attach.

Most factory cars had a ground from battery to engine, rad yoke and strap from head to firewall.

 

[Locomotion]

I like to use the washers that have little "teeth" around their perimeter to help insure a good ground to the surface you attach the cable to, even after cleaning off the paint.

 

[65 Dartman]

Most factory cars had a ground from battery to engine, rad yoke and strap from head to firewall.

The poor old early A's only had grounds from the battery to the engine and firewall to the head. Adding a ground to the rad yoke and/or inner fender would be a good idea.

 

[younggun2.0]

car does have welded in frame connectors. the connectors come thru the floor part way and are welded to floor pan. I do not have a roll cage in the car. sounds like i just need to ground the engine to firewall and then core support to frame rail and i should have all my bases covered.

does it matter that my heads are aluminum?

 

[godfatherofchry]

I don't think you can have to Meany grounds..I go to the junk yard and get all kinds of neet ground wires.and use 3or4 from motor to the frame.I also run a wire from the ing.box to the frame......just saying..........Artie

 

[67Dart273]

I am getting ready to rewire my entire car. I want to know what everyone is using for grounding there cars. I currently have my battery mounted in the trunk. i have 1/0 cable going from the battery negative terminal straight thru the floor and grounded to the rear frame rail. On the engine, driverside front cylinder head i have a 1/0 flat braided strap going to the driver inner fender where the factory battery would have grounded. what else do i need guys?

You PROBABLY are OK, but I'd feel better if the ground was hooked to the "same metal" as the battery. That is, the battery is grounded to the frame rail which is welded to and part of the main unibody. So I'd think a better place would be the front frame rail, or even the firewall

BUT

You can easily CHECK this

Pull the coil wire, and ground it to the block to disable the engine, and protect the electronics

Make a clip lead long enough to go from one end of the car to the other, no14 is plenty large.

Clip one end of the lead to the battery ground bolt in the trunk. Run it up front and clip the other end to your meter. Clip the remaining meter probe to your engine block.

Set the meter to read low DC volts (or autorange) and crank the engine while watching the meter. You are hoping for a very low reading, the lower the better. I'd say if you show less than .3V (three tenths of 1 volt) while cranking, you have a good ground. If you can, move the clip lead (may need a helper) to stab right into the battery post, and recheck. You should not see much rise

You can also check the voltage drop on the positive harness.

Clip one meter lead to your starter "big" battery stud, run the clip lead back and hook the other end (IF YOU CAN) directly to the positive post. Again, you are hoping for a very low reading, .2--.3V (three tenths) or less, and measured while cranking the engine

MORE than this with either test, means you have too--small cable, or bad connections somewhere.

One thing I've done "in the trunk" for the 3-4 cars I've been involved with was to ground to TWO points, which provide more surface area. On one car, I found a nice little copper strap (scrap) about 1/4" thick x 1" x 2" long. I ground the trunk clean, and silver brazed this copper into the trunk.

Also what helps is to use Burndy style two--bolt terminals--- again more surface area

Like these with the two mounting holes, and I see they make one with FOUR holes!!

 

[Oldmanmopar]

I have 6 wires going to my motor. 1 alternater, 2 dist. 2 water pump and 1 temp sender for fans. The motor is grounded through the steel mounts.

The battery ground is attached to the wheel house with the bolt shown in the pics.

 

[inkjunkie]

Last project I had I made the mistake of scrimping on the grounds, truck was efi and I paid for it. Battery to frame, motor to frame and even the though the car is a unibody I would still go from motor to firewall.....

 

[swifter]

I put batt in trunk ran a ground to the rear of the chassis with a pre-made battery cable,Ran a double o wire to the fire wall mounted with a 4 in 3/8 bolt and grounded everything with crimped ring terminals to the bolt also took pre-made batt. cables from each head to this bolt to ground the motor-No electric problems at all --Steve

 

[Austex73]

Yup, I learned the hard way, and didn't have a good ground when I put my motor back in. It used my shifter cable as part of the ground and it melted... couldn't even shift it. I quickly installed a 1/0 cable from battery in the trunk to the back of the block, and immediately noticed a difference when starting the car.