Hello folks,
It has been a while since I have posted anything on here, but I am in desperate need of some help today. Let me give you the car specs first:
1995 Pontiac Grand Prix
3.1 Liter V6
Miles: 225,000
Transmission: (salvage yard) 4T80E
The issue I am having is that my mother had a mechanic put the transmission in the car about eight months ago or so. My mother said that the car was running great, but the gas mileage did not seem to be where it needed to be. I actually took the car to work with me, which was two hours or so from where she lives, so that I could take a look at it in my friend's shop. I noticed on the way up that it was not going into overdrive. The transmission does not slip, and it pulls strong. I can do a manual shift through: first, second, and third fine. When I go to drive the RPMS never change. It doesn't even try to go into overdrive, almost like it's not even there. I have found a two wire plug on top of the motor that was left loose over by the alternator. I don't remember the exact color of the wires, I remember one was yellow. The plug length is probably just over a foot long, and the end is red in color. I have looked at several wiring diagrams trying to find where this creature goes, and what it is, but no luck. To me it's almost like lockup is not getting the 12v it needs to engage.
Here are some fluid specs on the tranny:
Color: Light red
Smell: Not burnt
Level: full at idle
Can someone point me on what I need to do to start diagnosing the issue. I really think the transmission is okay. It pulls really strong, and doesn't slip.
Thanks,
littlekatfish2003
