Okay. I'm stumped. I've scoured through my '84 Service Manual (I think the wiring is pretty much the same for an '87) and poured over the wiring schematics. I've replaced the ballast resistor, any suspect wires from the battery that I could find, the alternator, and the voltage regulator.

Here's the problem:

Recently, my 87 RC has been giving me trouble. At first, it just wouldn't start. I'd turn the key and nothing. I'd fiddle around with some wires, and jiggle the plug for the neutral safety switch, and then it would start. So I suspected a bad neutral safety switch, and I replaced that along with the plug, whose wires basically snapped as I removed it from the NSS. That seemed to fix my problem. For a day or so. Then the truck would just stop running while I was going down the road. Sometimes it would restart, and sometimes it wouldn't. I did some checking into the cobbled together fusible links on the drivers inner fender, and decided to cut them out and put in a fuse box (actually it was a mechanic friend who did me a favor when I was at work). So I did that. I put in all 20amp fuses for the four circuits, but the one coming from the big black wire from the alternator kept blowing fuses. The mechanic said to use a 30amp fuse. That helped, but the fuses would still blow. So I started measuring, and found out that the alternator was putting out 34VDC at that wire (and from the post terminal on the Alternator) at idle, and would not go any lower. I changed out the Voltage regulator, and that seemed to fix the problem. 14.5 volts. For a minute. Then it went right back to the 34v. I replaced the alternator (AutoZone checked it and it showed bad). I bought a new VR with the new alternator and put it in. There was no change. Still 34v. I checked the green wire for shorts. None. I check the blue wire for voltage with the ignition on. It showed battery voltage (about 12v now that I've been cranking it a lot) as it should. With the key off, the blue wire shows grounded (using ohm meter to determine that). I have replaced the ignition switch on the steering column, thinking it was possible a bad switch. No change.

I'm really at a loss here. Is there a way to determine if the VR is good using a ohm meter? I have four of them now, and two show .54 ohms resistance between the center (blue wire) post and the case, and the other two show .29 and .34 respectively. I don't know what the reading should be. Between the left post (green wire) and the case ground, none of them show any connectivity at all.

So what am I missing here? When I pull the green wire off the alternator while the motor is running, the voltage drops down slowly to about 1/2 Volt. When I put it back on, there is a spark as it is connected, and then we are right back to 34v at idle. I've seen it go as high as 70VDC at very fast idle.

Could I have just gotten another bad alternator, or could it have 'blown' from using the older VR before swapping in the new one? Any suggestions are welcome! Thanks!

**SOLVED** SEE POST BELOW