I did this over the weekend. What a difference! Thought I'd post some pics here and the parts I used. Hope someone finds this useful
I used a 5k linear pot that I purchased from Jameco Electronics. This is the part I used along with the ****.
Total for these parts was about $2.50. Shipping was more! (No, radio shack didn't have anything. At least not the one close to my home.)
The hardest part of the procurement process was trying to find some pins that would interface with the original TPS weatherpak style connecter. I finally found these from Radio Shack. Cost was around $3. It's a simple Serial type connector for computers. It also comes in a parallel style, but I didn't need that many pins!
Since my truck is a 2wd, I decided to mount the pot on the information center panel that's blank. This is where the 4wd transfer case info is displayed. This is the panel removed with the pot installed. Just had to drill one hole then a little "half" hole on the back for a pin that keeps the pot from rotating.
Here's the back of the pot with the wires soldered on. I shrink wrapped all the connections as well. The wire I used is a "repurposed" laptop computer power wire. It has 4 small conductors and is about 1/4" in diameter. I though it would be nice to have an extra wire just in case one decides to crap out sometime. This circuit carries very little current...it's only used to sense voltage...so conductor size isn't an issue.
I brought the wire through the firewall just above the throttle cable. It's easy to access from the engine bay. It's just to the right (looking at the firewall) of the head...between the head and the brake booster. I used a rubber grommet to protect the wire from the metal. This is looking up from the driver's floor.
And from the engine compartment.
This is the new pins soldered onto the wires. The wire colors pretty closely matched the colors in the wiring harness. The red is the middle wire, or reference voltage. The white and black go on the sides. I just kept the orientation the same on the pots. The TPS is just a pot mounted upside down. So I flipped the harness connector, read the wire colors, and soldered the wires to the new pot in the same order (with the shaft sticking up). If you get the outside wires mixed up, it's not a big deal, the pot will just work backwards at that point. Just flip them and it will work fine.
I was a little worried how to properly space the pins to solidly fit the connector. As it turned out, after the shrink tube was applied, the spacing was perfect.
I then applied another layer of a larger size shrink tube to cover the wires and to hold the pins stable.
I then applied a third layer of an even larger shrink tube to cover the whole thing and to hold it together.
Here it is all tied up and ready to roll. I left the TPS in place just in case anything should happen to the pot. I can just disconnect the wire and plug in to the TPS.
And here's the final product on the dash.
As always..."I should have done this ages ago!" I love it. It will shift to O/D at 35mph when the **** is at about the 9 o'clock position. If I turn the **** to about the 11 o'clock position, the shift goes up to around 50 mph.