[W1ldcat]

Checking a circut and checking ground are diffrent. Checking a circut you are checking between + and - checking ground is negitive to ground and that should be 0, no reisitance.

[kraused]

I went to a sterio shop and bough zero gauge wire and connections .I figured if sterio guys use it ther must be a logical reason.They have 0 all the way to 18 gauge its alittle pricey bought can get in many colors and they hall the ends for each size and battery connection.

[Aussie]

Fantastic mate, had heaps of probs starting the car and after many mods would not run at it's best, engine to chassis ground has fixed it all. Great info Juan

[ChargedGT95]

Does anyone know if a bad ground could cause only four of eight cylinders to fire? I would have thought that a bad ground would cause none to fire, but right now mine is only firing on the same four.

[farqy]

Good thread on grounding. Enjoyable read. Not sure if a bad ground can cause one bank to not fire properly, but keep in mind that electricity in a car needs to flow from the battery, to the ignition, to the spark plug, to the OTHER side of the spark plug, to the head, and somehow back to the other side of the battery. Also keep in mind that most head gaskets are not very good conductors...

If one head is not grounded very well, it could certainly cause weak or no spark on one side.

I noted that someone said that Aluminum is a poor conductor. Actually, aluminum is a BETTER conductor than copper, the problem is that aluminum oxidizes very easily (read=instantly) in air, and the oxides are very resistant to electrical flow. For a while in the 60's and 70's you could get wiring for a house that was aluminum, but after a lot of house fires due to high resistance and heat, copper became the only way to go. You can run grounds to your aluminum parts, including heads, but you have to make sure you have a fresh surface, by sanding or scraping, and then use a di-electric grease to keep oxides off of the contact surface.

Another major effect of bad grounds that was missed is that if you have a bad ground, electricity has a way of finding its own way back to the battery, so when your car is running poorly, the current is likely running through your car in long ways. The very bad side effect of this is you get stray currents in your engine. Stray currents cause your coolant flowing through its passages to form bubbles along the current lines, and these bubbles implode on themselves, causing cavitation, especially along cylinder liners. If you want to crack a cylinder wall, having a stray current is the best way to do so

I guess what I am trying to say is ground your aluminum parts, just do it right, and if you have bad grounds, you can have worse problems than hard starting.

[The Greek]

Copper and Aluminum shouldn't touch one another, they will corrode in no time and cause a bad connection. OK, here's what I do when I attach a copper lug to an aluminum surface. I place a stainless steel washer in between them. This way the copper isn't touching the aluminum. In fact I use stainless fasteners on all of the battery related cables. Stainless is a good conductor and of course, won't corrode.

NAPA sells battery cable in bulk, by the foot, in whatever gauge that you want. I personally went to 1/0 for my trunk mounted battery.

If you run both the positive and negative cables to the front of the car, run them next to each other. This creates a magnetic field that actually allows current to flow more easily with less voltage drop due to the length of the wire. Be aware that if you run too small of a gauge wire that you are restricting current flow and will have a greater loss of voltage through the cable. If you wonder where the voltage went, it's being transferred into heat because of the resistance to the current flow created by the small wire.

4 gauge wire from the trunk is on the small side in my opinion. I went to 1/0, but that is on the large side (It's overkill, I like the insurance), for best current flow. A good range to use is, 2 ga. up to 2/0. The 2/0 would be for a huge high compression engine. If the 4 ga. works for you, that OK, not all systems are the same. But---

The ground cable should NEVER be smaller than the positive cable. (Main ground to battery)

If you mount the battery in the trunk, use a sealed box. (Optima Battery not necessary). If you don't use a sealed box with a provision for a vent, all of the corrosive gasses emitted by the battery, (This gas is explosive too!), will go to work eating up everything inside of the trunk.

I used battery post clamps that have a threared stud on the end with a wing nut. I crimped wire lugs to the cables. Now all that I have to do to remove the cable is unscrew a wing nut, (stainless of course).

Both cylinder heads should have a ground cable that attaches them to the grounded engine block. As said before, head gaskets don't conduct electricity and a possibility of a poor ground does exist. This can have an effect on the firing of the spark plugs since they depend on a ground path through the cyl. head.

Fitting an appropriately sized star washer between the ground mounting surface and the cable lug, with a coating of dielectric grease will help to insure a good contact.

[tmoss]

using a "no-ox" electrical connection compound will address any dielectric differences in metals and prevent corrosion.

[1989gtfifty]

Thanks man i will definitely try this

[ravensfan28]

Originally Posted by farqy

Good thread on grounding. Enjoyable read. Not sure if a bad ground can cause one bank to not fire properly, but keep in mind that electricity in a car needs to flow from the battery, to the ignition, to the spark plug, to the OTHER side of the spark plug, to the head, and somehow back to the other side of the battery. Also keep in mind that most head gaskets are not very good conductors...

If one head is not grounded very well, it could certainly cause weak or no spark on one side.

I noted that someone said that Aluminum is a poor conductor. Actually, aluminum is a BETTER conductor than copper, the problem is that aluminum oxidizes very easily (read=instantly) in air, and the oxides are very resistant to electrical flow. For a while in the 60's and 70's you could get wiring for a house that was aluminum, but after a lot of house fires due to high resistance and heat, copper became the only way to go. You can run grounds to your aluminum parts, including heads, but you have to make sure you have a fresh surface, by sanding or scraping, and then use a di-electric grease to keep oxides off of the contact surface.

Another major effect of bad grounds that was missed is that if you have a bad ground, electricity has a way of finding its own way back to the battery, so when your car is running poorly, the current is likely running through your car in long ways. The very bad side effect of this is you get stray currents in your engine. Stray currents cause your coolant flowing through its passages to form bubbles along the current lines, and these bubbles implode on themselves, causing cavitation, especially along cylinder liners. If you want to crack a cylinder wall, having a stray current is the best way to do so

I guess what I am trying to say is ground your aluminum parts, just do it right, and if you have bad grounds, you can have worse problems than hard starting.

sorry to correct you but aluminum is not a better conductor than copper. metals rank in the following order :silver,copper,gold,aluminum,nickel,zinc,brass,iro n,all the way down to steel which is about the worst conductor.
The reason they used aluminum in the past was because of the heavy demand for copper by our military.it is also much cheaper than copper.

[alexcor]

i just moved my battery to my trunk and grounded the - cable to the rear shock tower. i also removed the - battery cable in the engine compartment. I noticed the car is a little slugish on starting and the idle is surging. so you ground the cable to the sway bar mount and to the back of the head? my old cable was grounded to the front of the engine block, can i just do it there?

[The Greek]

The ideal situation would be to have a ground cable to the body from the engine block and from the engine block a ground to each cyl. head and a ground to the intake manifold. You should ground the intake only if there are any electrical sensors/senders or injectors mounted on it, otherwise it's not necessary there, but....

If you are using an aluminum intake, a ground to it may keep the electrolysis down to a minimum. An electrical current caused by the engine coolant flowing through it. This will eat up the aluminum in the coolant passages and, (this is the bad part), the machined surfaces at the coolant passages where the intake gasket sits will be pitted like all get out.

One more place that needs grounding is the timing chain cover for the same reason as above, it has coolant flowing through it and it's aluminum and it gets pitted too.

There is a radiator cap for Mustangs that has a sacrifical anode that is connected to it. It sits in the coolant flow and gets eaten away instead of the aluminum parts on the engine. I use this in addition to the extra ground leads.

When mounting a battery in the trunk, if you are using the regular design wet cell battery, mount it so that the battery sits with the battery posts facing the right and left. This way the battery's internal plates won't have a tendency to contact one another and result in a shorted battery.

[panteraozz]

cant see the pictures juan

[NewtoGT]

Decided to do this upgrade since i was having issues on slow starting, and a bad ground from the battery. Well, i ran the battery ground to a new location other than the timing chain cover, and went to replace the engine ground strap and to my surprise, it was attached to the engine and not attached to the firewall at all, just hanging there. Finished the replacement and it sure enough makes a huge difference on starting and also to some degree has got the issue of idle surge straightened out a bit, it used to idle in the 900-1000ish range, now is sitting fairly steady around 800. Thx for the info Juan.

[dave1170]

This is a must do upgrade for any fox! I've had slow start and idle issues since I bought my Mustang, this upgrade solved all these issues. Great post Juan!! Thank again -Dave

[AT68]

For ground attaching points, I welded a stainless steel bolt to the framerail up front for the engine ground, and one in the trunk for the battery ground. I used 0 gauge welding cable shielded in split 5/8" heater hose with wire ties and insulated clamps to connect the battery in the trunk to the solenoid up front.