Well guys, I don't know if any care but I did get the overcharging problem on my 92 fixed finally, after I gutted my harness. I just knew it was going to be something so simple that I would feel stupid after finding it but that was not the case. I'm still not completely sure of the root cause of all the problems but all is back to normal operation.

I think I was getting some sort of back feed somewhere, maybe even through the ground somehow because as I mentioned I completely bypassed the PCM with a firewall mounted external regulator and still got a overcharge. Full field on my system before the repair was around 18 volts and I was getting around 16.

Anyway after I found that the ignition switch was burnt and the blower motor wires in and out of the switch had burnt off insulation and not getting proper continuity through those two terminals, (even though I was having no issue with the blower motor), I replaced the switch. After that I had a start no crank situation and no check engine lamp, (so I couldn't check for codes), I found I was getting no power to pin #3 at the PCM.

That's when I started looking for a blown fusible link in the harness and found that there was none for that circuit, I started gutting the harness back to where I found that the splice for the ASD, fuel pump, blower motor fuse and the wire to pin #3 had gotten hot enough to burn the wire to pin three and also had shorted what was left of that splice into another splice, I think the front park lamp or turn signal splice. The only indication that I was having any problems with that is that when I would use a turn signal or flashers the voltmeter would pulse with the lamp. That had been going on for a long time but it doesn't now since the repair.

When I replaced the ignition switch I decided that I would make sure that it had good ground to the steering column, I've had problem with that before, all that grounds it is a U shaped clip that slips around the plastic isolator where the column bolts up to the metal frame. It's captured good to the frame with the stud and nut but only has touch contact with the column. I soldered a 10 gauge wire to it and put a short sheet metal screw into the column making sure it didn't interfere with the steering shaft. Hope that eliminates any more hot wiring to the ignition switch.

Now I'm charging at around 14 volts and all is functioning normal as far as I can tell. It will take me a couple of hours to get the harness all taped and new conduit/sheathing back on but what a relief to have that mind bender fixed...Dennis

 

I'm glad you got it fixed.