OK... Heres my problem.. 1994 7.3 idi turbo... e4od Trans in her... no fuel gauge working.. no rpm gauge working.. When in D, the truck takes off like a slug... i can shift through the gears and once in drive it will kick from third to fourth... ok easy.. replaced tach sensor.. still nothing.. ok must be the TCM right?? nope that checks out fine... so we hooked up a TCM tester to the trans... all the gauges worked and truck shifted perfectly... any ideas...??? it must be the harness right?? but which one???? any help would be great..

 

clean connectors? only one wiring harness goes from drivers side wheel well down to two connectors to tranny and i think transfer case

 

I'm told he transmission harness and engine harness are separate

 

yes when i did my manual swap i had the chance for the manual harness but i just hot wired my auto it goes right under the brake booster but i believe the tranny harness ties somewhere into the gauge computer in the dash

 

did you check the fuses in the power distinction box under the hood yet? there's a couple (im pretty tired out so i didn't look it up to see which ones lol) that if they blow,will take out the tach.with the E40D,no tachy = no worky.