chuck craig

Is there a way to over ride the TPS and mechanically/electrically engage the overdrive when you want it?

Coagulation

Yes install a switch to ground the overdrive solenoid.

infidel

Here you go http://www.tstproducts.com/Torque%20...p%20Switch.pdf

Wet1

Could you please tell me exactly where this is?

Wet1

I'm no expert, but isn't this just for locking the converter, not the OD?

kell

If the problem is the tps, you don't have to jumper the overdrive solenoid. You can jumper the tps output to ground instead and solve the problem that way, at least for my model year. When I finally figured out my tps was at fault for my '94 not shifting into overdrive, I wired a switch in the cab to ground the tps signal output through a 1 kilohm resistor. The 1000 ohm resistor is a precaution to keep from grounding out the 5 volt reference that the PCM supplies to the potentiometer in the tps. I think it has about a 50k pot in there, and if the wiper is set all the way at the hot end, you don't wand to short that wiper to ground.
Grounding the tps output makes the computer think you have let off the throttle, and it will shift into overdrive.
Haynes manual has a diagram for the tps connector, but it gets the ground and reference pins reversed for the 47RH, I notice. At least the output (Haynes calls it "signal") is the middle wire, so you can't go wrong. Haynes also calls the 47RH a 37RH, and apparently has some other little mistakes like mixing up inch-pounds and foot-pounds.

winkle

Here's a good write up which might help you with what you want to do:

https://www.dieseltruckresource.com/...d.php?t=142641

https://www.dieseltruckresource.com/...ad.php?t=42003