I need help
1998 dodge 5.9L cummins auto 3/4 ton ext.cab. 90,000 miles original

About a year ago, it started to shift in and out (tougue convertor) at 40 mph. Had it to three shops. 1 couldn,t fix 2nd shop hade it for 6 days, finally said it was starter. I said give me my truck back. 3rd, put a new starter on, no change. Since then, I have cleaned every ground terminal, ran a new gr.wire from computor stud on fire wall to neg. side of aux. battery, 2 grd. wires from block to frame in differant places. Still shifting in and out. By the way, motor temp has no bearing as it shifts goofy at any temp. The last shop I was to said everything else checked out normal. CAN SOMEBODY HELP MY TRUCK?

Thanks in advance

 

Welcome to db
Have you checked the throttle position sensor?

 

Sounds like you have AC noise coming from the alternator. Causing the Trans to jump in and out of lock up.

 

I put aluminum foil around all the ground wires on the passenger side of the engine going to the battery. Pay special attention to the one that goes near the alternator.

I did also reroute the alternator wire with a larger replacement that now goes along the front of the core support, but when I did that it didn't fix the noice. The aluminum foil did. I had tried every other recommended fix prior to that.