I just wanted to share with the group an easy fix that I came upon for 2006 Ram tach issues. The issue is with the tach registering lower than normal, or, in my case a tach that completely stopped working. The problem is from the black plastic cover that is screwed to the cluster. Apparently, this cover causes the circuit board to flex in such a way, that causes the tach to malfunction.
I have followed several threads that tell you to reflow the solder on a couple of chips. I did not want to do that, as it is possible to cause a short that will fry other components. I ran across a thread in the Diesel section that I thought sounds logical.
The post said to loosen the torx screws that are on the perimeter near the tach, and to completely remove the screws that surround it. I did this, and my tach went from completely non-functional, to working perfectly. It has been 2 weeks since I did this, and that is enough time for me to feel that it is permanent.
I have had the cluster out several times to try and figure out why the tach stopped working, and each time I put it back in, it would work fine for a couple of days. That got me to thinking it's not a faulty step motor, and that it was more related to the board. The time before I did this trick, was to replace the bulbs, and also to reflow the solder. I backed out of the reflow, as it just looked too risky. Like I said, after that the tach worked fine for a few days, then just died.
2 weeks now, and perfect.
If you have this problem of a malfunctioning tach, give it a try. You have nothing to lose.