I just got a almost new but used tach from a good friend of mine. It's an Isspro tach that mounts in the pillar pod. Well I found the plug under the dash and plugged all of the correct wires into it. The light in the gauge works with the lights on the truck. But when I ground the wire coming out of the gauge, the needle jumps up to 1500 for a second then it goes back to 0. I heard the crank position sensor goes through the computer. What I would like to do, is just splice into the sensor wire under the hood and just bypass the computer. Would that be possible. I noticed there is 3 wires coming from the sensor. The friend had it plugged into his 93 Dodge Diesel just the same way as mine but mine don't work. Thanks for any help!!!

 

The first ISSPRO tach I had would not work at all. Got another one and it worked. My tach jumps up for a moment when I turn on the key but does work. I would recheck the wiring hookup, at one time the instruction were incorrect about the wire colors.

Jim

 

http://www.isspro.com/installation/IS236A.pdf

Here's a link to the Isspro website instruction sheet for installing a 2" tach. It explains the correct connection details, but I'd do a search here on DTR for the tach install instructions - they are much more clear about the '2 grounds'(there are 2 black wires in the factory plug it seems) issue, and how the color-coding matches up 'tween the Isspro harness and the Dodge plug. Anyways, my Isspro tached connected easily and worked right off, not to brag, but yours probably will when connected correctly. Hope so, good luck! :-)