Back in April I posted about a torque converter lock-up problem that I was experiencing on my 2000 Cummins 2500. Since that time, every time I drove the truck, at about 45 MPH the torque converter would jump in and out of lock-up. For months I dealt with it by stomping on the accelerator or eventually it got so bad I had to shift out of overdrive, especially while towing. I tested what I could on the APPS and the brake pedal without solid conclusions. Anyway, it eventually got so bad I had to do something. As a last drastic measure, I tried these two fixes, and if they hadn't worked I was off to buy the $480 APPS the next day. The fixes were to "reset" the APPS and to reroute the alternator ground wire. Well to my surprise, one of the fixes worked (don't have a clue which one) and the problem hasn't presented itself again in 2 weeks/500 miles. The only suspicious thing I observed was the ground wire was laying across and in contact with the alternator, so I relocated it and shielded it. If that was indeed the problem, kudos to Tony Garcin at Dunrite Converters for sharing! It could have been a long time before that was discovered. While I don't know which fixed it, if the problem reoccurs at least I know it's electrical which gets me somewhere (and I suspect if it's the APPS it will resurface).
Anyway, thanks to all who responded. I offer this in the hope that it helps someone else along the way.
While I was on a roll, I finally installed the fuel pressure gauge that Roy and Tom had advised years ago. It was an easy fix with the parts from Geno's.
Jack
How to reset the APPS:
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