Originally Posted by ctm
also look at this diagram, it is from JYG or hammer , I can't find the original thread, but I have the diagram that shows an extra ground for the distributor. I did this and it makes a big difference.
Grounds are something that are overlooked so much you simply wouldn't believe it!
This is absolutely true.
AMC (and most other vehicle manufacturers) wouldn't pay the extra $6 per vehicle to have dedicated grounds added to the wiring harnesses.
Chevy stated that it took an extra $6 per vehicle harness to add dedicated grounds for the military in 1983, and since all vehicle harnesses cost about the same amount...
As long as your vehicle lived through the warranty period (usually 12 months/12,000 miles to 36 months/36,000 miles)
Not having dedicated grounds wasn't an issue, and the company saved $6 per unit.
After the warranty period, any electrical problems were pretty well known to the dealership mechanics, so any electrical issues the owner had were money in the bank for the dealership.
If you got fed up after the warranty period, you would buy a new vehicle to get away from the problems...
This too was money in the bank for the dealerships.
Military vehicles required dedicated grounds for most accessories, even in fleet vehicles (non-combat rated vehicles that usually had much more extensive modifications) since they would be used long after the average warranty was expired...
If you pay attention to the diagrams I've posted, not only do I run a battery cable to the starter to ground it directly from the battery,
But I run a heavy wire to a grounding post on the fender, and run dedicated grounds from that...
Since the ignition produces between 20,000 volts and 45,000 volts, it needs a good ground, or your ignition coil will heat up and cook it's self...
A simple 12 Ga. dedicated wire to the head(s) will make sure your ignition spark energies have a good ground...
Run it off the grounding post on the fender.
That same ground can be run over to the ignition module and give the module a dedicated ground.
Costs you nothing but a connector and a little time, and gives your ignition module a new lease on life, and gives you faster, cleaner switching for the ignition coil, and that will result in more usable spark energy....
Since your alternator has a dedicated 12 volt, 10 gauge positive wire,
Since every electron your vehicle uses is produced by that same alternator,
WHY NOT GIVE IT A DEDICATED GROUND?
Only takes a short run of 10 Ga. wire from the grounding post to the alternator case, and no more alternator problems from bad grounds!
Your dedicated grounds should include, but not limited to,
1. The dash, so your gauges and wipers work since they are grounded there,
2. The tub, so your appliances work,
3. The grill shell, so your head lights/turn lights work,
4. Rear lights, tail, brake, turn, plate, backup, ect. should have a dedicated ground.
5. Fuel tank, so the sending unit works correctly.
6. The engine block, and in particular, the head(s) so the high voltage from the ignition has a clear path to ground,
7. The ignition module, so it doesn't have to fight for ground through the distributor housing.
8. The STARTER should have it's own dedicated ground cable that attaches directly to the starter housing!
This is the highest amp load your vehicle is going to have, so DON'T TORTURE THE CURRENT PATH!
9. The alternator. Since every electron your vehicle uses is produced in the alternator, you REALLY need a dedicated ground for it!
10. In my case, the electric radiator fan, electric fuel pump and a half dozen other things like air compressor,