Anyone know what color the wire is that comes off of the gauge cluster for the tach signal on a 2001 ram 2500 gas?

 

You can download the factory service manual for your truck from here. Wiring diagrams are in section 8W. However, I think the tach, and all the other gauges..... get their clue what to display from the communications bus. Basically its a mini-network in your truck. The PCM simply tells the cluster what it should do with the various gauges and lights.

Try a cluster test. With ignition off, press and hold the trip/reset button, turn the ignition to On. (not start) The test will turn on all the lights, and run all the gauges thru a full sweep. Does the tach do it's thing properly during the test?

 

Thank you! Would you happen to know where I can find a PCM wiring diagram?

 

In the service manual. There are connector pinouts in the wiring section as well.

 

I must have missed it. Thanks again!

 

Well, it IS a pretty fat book.

 

with rather thin pages... one might say bible-esk.