I recently installed a new (actually used but known working-thanks Adam!) alternator in my GT. I was hoping to solve my low voltage problem. I get good voltage when the car is running, but as soon as I hit the brake lights, turn signals, headlights, or the sub hits, my voltage takes a dive. If the fan is on and the headlights are on then my radio will sometimes shut off momentarily. I have complained about this many times on the forum before. Now that I know it isn't the alternators fault, I am assuming that I have some bad grounds. I know that I have one, but I am kinda skeptical that the one ground causes such a dramatic effect. It very well may be the one ground, but I figured I'd be thorough and check everything. This is where my question comes in.

Can anyone provide for me a complete list of ground wires in the engine bay?

Any help is greatly appreciated.

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go to the local parts store and have them test the bat. if/when a new bat is needed buy an Optima

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Rich
white 86 se, 2" drop, coil overs, KYB's. CRX intake, ported manifolds

I had the same issue for a long time, ended up toasting alternator after alternator. They finally offered me my money back so I could go elsewhere, and I refused. Decided to give it one more try.
THEN I started looking around the engine bay, and noticed that the ground wire going from the transmission end of the engine block was no longer connected to the frame. That was the only ground lead I had to the chassis of the vehicle.

I started hunting around, and noticed the small black wire coming from the ground post on the battery terminal was not connected to the battery tray either. I took an old battery cable I had laying around, crimped on a large fitting on the end of it (Terminal fitting for 4 guage or larger wire) and ran a ground from the upper cable mount location on the forward head of the V6, to the decklid hinge located next to the battery. The bottom 13 MM nut comes off, wire brush the metal there, and then slide the lug over the stud, reinstall the 13MM nut, and tighten it firmly, then treat the metal over it with a terminal cleaner and protector.

On the V6 forward head, located being the Engine Hoist loop, is a 15MM bolt going into the head, it is approximately 1" long, and has the ground lead coming from the battery underneath it. Attach the other end of your new ground cable to this bolt, and tighten.

This solved my entire problem, system works like a charm now. If you really feel the urge, reattach the small ground cable on the transmission end of the engine to the chassis under the clutch/auto tranny lines on the Driver's side of the vehicle.

You can never have too many grounds.

Synthesis - You are my SAVIOR!

That sounds like exactly what I see in my car. The lead to the battery tray was fried, but I fixed it with some 8 guage. It is connected to a kinda rusty area, but I'll fix that. And my frame to tranny lead is also severed. I will do just what you said and follow up. Thanks a lot!

BTW, $Rich$, I replaced the battery with a Champion not long ago. An Optima will come later.

There are or should be 4 main ground ties.

1. braided block to body ground.
2. Battery to body
3. tranny to body.
4. Block to Battery (The big battery cable.)

The tranny to body is a backup. At least that's how I always treat it. It isn't able to cary as much current as the braided one. New braided straps are cheap at most parts stores. It's a pretty generic item.

The braided strap is critical... This is the one ment to carry all the return power between the body and block. It has to go to solid locations on both ends.

Grease the ends with Brake grease or something else that is hard to wash off. That will prevent corrosion in the hardware. You MUST make sure all paint rust and dirt are removed from whereever you attatch these cables.

Don't assume the battery heavy block ground is good by looking at it. You'd be amazed how bad a battery cable can be and still look ok. They can had major corrosion inside the insulation and inside cast battery ends. (Tubular crimped ends can also hide major corrosion.)

If the battery to body wire is bad, replace the cable. If the wire went bad then the wire inside the battery terminal end may not be so great either. Water can whick into the wire a long way.

Battery cables are pretty cheap. Always replace both at the same time.

Whenever you can get them, use an AC Delco battery cables. AC gives you plenty of wire on the thin lead. Just cut ot to length and put a new weather proof crimp on it. (Those have self sealing heat srink tube on them.) With most other brands you'll have to extend the wire, making even more places the wire can start corroding.

You also need to check the + feed from the alt to the main terminal below C500. If that is crappy you get the same problems as a bad ground. (I.E.. Big voltage drop under load.)

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Screamin' Yellow Zonkers... If it's Screaming and Yellow, I aint eatin it.

Thanks a lot guys!

Fixed my battery to body ground, and made one from the block to the body. Now I can have my turn signal, headlights, system, brake lights, and radiator fan on and still show 13 volts! I am going to replace the tranny to body ground eventually, just for yuks. Question is, where on the tranny does the ground connect to? I only have the body end still left (at least that I can find).

Again, thank you very much.