91.5 Intercooled. Not charging, no start, no crank

[dirty-dozen]

I have a 91.5 intercooled that is giving me electrical nightmares. While driving down the highway I noticed I had lost all charging. Voltage gauge showed below 8 volts and my battery had been drained. Thankfully I have a gutted FSS so my truck still was running and driving. When I got home I shut it down and replaced the voltage regulator. Went to start it and just got a click. All of my electronics appear to be working fine. Wait to start light as well as all dash lights function and cycle properly. Blower motor, headlights, etc. all work. I got my alternator and battery tested and they both check out fine. I jumped the terminal on the starter and it cranked over and fired right up but still not charging. I have inspected the fusible links as well as replaced the starter solenoid and still have nothing. I am running out of Ideas. I can feel and hear the starter solenoid click when I turn the key to start so I am assuming the ignition switch is okay. Im really stumped on this one. Any help would be appreciated. Just to be clear, This is an external voltage regulator truck. It is not the same wiring as the 92-93 trucks. I do not have the 3 relays on the fender like on the newer 92 and 93 trucks. Please help me out guys, I have run out of ideas.

[cmann250]

When most auto parts stores test an alternator, they spin it at something like 3000 rpm. It's bound to make some sparks at that speed, but what diesel spends any length of time in that rpm range?

With the engine idling, what does your multimeter say the voltage at the battery is?

[Tacoclaw]

Just to check, and I know it's a stupid question since you specified the 3 solenoid thing, but you changed the silver relay on the driver's inner fender that goes to the starter solenoid, right?Any way you could get someone to hit your key while you gave the solenoid on the actual starter a good tapping?

I know when my VR went out it wasted my alternator and starter somehow. It may have ruined your alternator.

[peobryant]

For what it's worth, everytime I've had a charging issue it has either been the voltage regulator or alternator. The last time I had installed a reman alternator from NAPA and it lasted less than two weeks. I had it tested and it checked out fine so I replaced the voltage regulator. Sill wasn't charging so I pulled the alternator and had it replaced under warranty, installed the new alternator and she's been fins since.