Man funny you mentioned the ground wires. I went home yesterday and checked the main ground wire running from the battery to the block. It had some corrosion on it and looked like it had gotten hot. I checked continuity from the bolt that holds it on the block back to the negative post of the battery. It was bouncing from 500-750 ohms. So I cleaned both ends of the cable. Started the car without the alternator output hooked up. Same thing 30 volts DC at Idle. I had a 98 Neon so I was curious and started it without the alternator lead hooked to the starter and guess what 33 VDC. I knew it was OK. I put another fuse in the "fusible link" (all that I could get from AZ on a Sunday) started the car with the alternator output hooked up and this time the fuse took about 15 seconds to blow. Before it blew instantly. Making progress. I started looking for ground wires and found a flat braided ground that looked frayed some anyways but had melted the rest of the way through. I fixed it and put in another fuse. This time about 45 seconds to blow. So I checked the DC amps that was running through the alternator output wire 35 amps BINGO! I swapped out the "fusible link" with a 30 amp fuse in it and installed an 8 AWG wire about 4" long and started the car. 14.4 volts at the battery and pulling 30 amps. All of this was done with the external regulator.

Curious, I unhooked the external voltage regulator and hooked up the PCM to control the alternator voltage and it's still good. I lucked out with that much current flowing through the system to fry a ground, alternator and a fusible link and not take out my computer... someone was looking out for me.

 

Hard to believe multiple ground wires can be so important, but I think the smaller the gauge wire is the trick.

Glad you fixed and didn't fry the wiring harness =)

 

Yep... Thanks for your help.