AKGriz

I agree! When I saw your article I knew I had to do it--sure glad I did. Reading that one article paid for my subscription for numerous years!

Changed out the alternator, only got to run it a few minutes before work--but have charging voltage and overdrive works without blowing the fuse! Still going to have tranny guy work his magic this weekend, but looks like the alternator was the issue. Thanks to all for their help!!!

Disconnected the field leads on the alternator and took her for a drive. Interestingly enough, the transmission shifted normally (including into overdrive and lockup) and the fuse did not blow. Consequently, there is now a new (as in "new," not rebuilt) alternator sitting in the backup vehicle which I will install in the morning. More to follow. Thanks, Mopar1973Man!

Yes, I'm wondering if I have a ground issue. I've had those bolts out twice in the past 2 weeks and cleaned them up. We're going to pull the transmission relay this evening and go for a ride, and she's going to the tranny guy for solenoids/harness Friday night. I'll update after the tests. Unfortunately our electrical rebuild shop closed down a few years ago (couldn't compete with the big companies)--otherwise I'd have him tear into the alternator. Closest shop is in Anchorage, 367 road miles away. I am prepared to hit NAPA up for a new one, but that's no guarantee of getting a good one either!!!

Excellent thoughts. NAPA tested the bosch as good, for whatever that's worth. I did emory cloth the firewall to PCM connection last week. A/C is <0.1A. We're going to pull the transmission control relay at the PDC (should have 3rd gear only) and go run it to see if we have charging without interference from any tranny issues. If that works, we should have eliminated the alternator as a source of the problem. If it doesn't work, it points directly to the alternator having a short as the wire itself as a problem has already been eliminated through ohm testing. Does this sound like a reasonable plan? There is no Holiday Inn Express in town, so I'm kind of out there flapping....

No, I have not. I will definitely check it out this weekend when I get the truck inside (it's possibly headed down to minus 50....). That's crazy! Some solder might work wonders.

Here's my tale of woe. '99 3500 5.9 Cummins A/T--Started out with the the torque converter lock/unlock issue, found the cure purely by accident (pulled the alternator charge line which was lying directly on the alternator away from the alternator, and problem went away for a couple weeks until the line returned to its original position--ah ha!!!). Traced the charge line, and ended up basically doing the W-T Ground Mod, things ran perfectly for about 4 years. I could not believe that crazy ground splice on the port side of the motor--engineer must have been hitting the sauce on that one. Wish I'd found this site back then!!! Forgot to mention, I bought the truck used in 2015 with only 46,000 original miles on it--when I had the tranny rebuilt at 90,000, the tranny guy told me there were some non-OEM parts in the tranny--in other words, someone had been in there trying to fix the torque converter issue thinking it was a transmission problem. This has been a source of great amusement to me, as the original owner sold this great truck because it had an "unfixable" transmission problem (and of course didn't tell me)--so thanks, MM1973, for letting people know about this easy fix even though I had to find it by accident! While on a trip out of Alaska, got a no-charge condition and ended up doing an external regulator fix to get home. Never liked the external regulator, as frequently the voltage would run high (15+). After reading MM1973's article on the fuse, decided to implement it and restore wiring to original condition (with the addition of the 5A fuse)--purchased a used PCM, sent it off to be programmed to my VIN, installed it when it returned. Lo and behold, the voltage was in the low 14s and the vehicle ran great with the exception of Brake and ABS lights (turned out the VIN programming did not take; the ABS module did not like an incorrect VIN!) and an occasional "surge" in RPM. Meanwhile, I sent the original PCM in for repair. A friend rode with me and monitored system voltage on his scanner--there was a very slight "spike" of 0.1V every time the "surge" occurred (could only see it on the graph). Strangely enough, the PCM rebuilder reported there were no problems with the original PCM (I asked them to replace that circuit regardless, which they did, and then tested for heat and vibration). When I received it back and installed it, all was well with the exception of the tranny surge--it seemed to be bad one day, and disappear the next. It was not throwing any codes, at least that my Edge reported. About 2 weeks later, while driving to work (temp was about minus 30), the surge got pretty nasty so I locked out the overdrive to smooth things out. Just before I pulled into work, I pushed the overdrive switch--it didn't shift, and my voltage dropped to 11.9. As I suspected, the 5A fuse had blown. I replaced it with a 7.5A, but still had no charging. I'm guessing the original PCM has acted up again. So I put my backup PCM in and went for a test drive. Voltage was good, and she shifted into overdrive. Problem solved, or so I thought. I turned around to head back to the shop, and got on it a little to ensure things were working properly. Instantly the voltage dropped to 11, and no overdrive. Edge pulled down a P1765, P1682 and P0753. Put the ohmmeter to the dark blue line coming off pin C3 25 to the alternator, have good continuity and no continuity to ground (same with green wire from C2 10). Going to have transmission solenoids and wiring harness replaced this weekend based on transmission guy's previous experience with similar issues. Based on the wiring diagram, it seems it has to be a transmission circuit issue. But I'm still totally baffled as to the origin of the no charge situation--either the PCM rebuilder doesn't know what he's talking about or I've got some real gremlins running around in my truck (he said it tested good, and it worked well for a couple of weeks, but now this--and after I put in the protective fuse). And full disclosure--I'm totally dumb when it comes to understanding automatic transmissions and 12V systems, but I did sleep in a Holiday Inn Express once. Sorry to be so long winded! I'd like to hear other members' ideas on this. I'll report back after the solenoid/harness replacement this weekend. Thanks in advance!