Can anyone point me in the right direction for the tach wire under the dash? I can see it in the schematic, but can't find it on the truck.

 

I do not know if your particular year truck had one, I know mine does and it is a 93 so i would say yours might. If it does, it would be around your parking brake and hood release ****. It is a 4 pin flat connector and it pretty much dangles there. I installed a tach in mytruck, but did not use that wire. It was too expensive of a set up for me.

 

Thanks for the tip, I know the connector you are talking about.

Why was it too expensive to use that tach signal?

 

I found the wiring harness and tach at ISSPRO and the harness and tach which were both sold seperatly would have costed me more than it would to buy a tach from AUTOMETER. The tach that I found from Autometer costed me around $120.00 after shipping so I decided to Buy it. The tach from Autometer was simple to install and it comes with all the mounting hardware.
The tach is set up by a small reciever that clamps on the side of your alternator and a wire to the tach. I had mine set up in less than 3 hours in zero degree weather with no garage to keep the wind off of me.
If you are interested in buying the tach, I got mine from Summitracing.com and the model number is 2888. I love mine. Hope I could help ya,
Wheelo

 

I'm going to mutimeter each of the four wires to find the pulse, then hook my timing light and see if it's regular and consistent with RPM. If it is, and the voltage in not too high I will stick on a regular tach.