Hello all, I am finally trying to diagnose the problem with the tachometer on my 1974 SR5 Corolla. Unfortunately, both of the shop manuals I have just skip over the tachometer entirely and assume that the car is equipped with just a speedo and multi gauge. I understand somewhat the theory of how an electronic tach works, but I cannot wrap my head around diagnosis of my actual system. The issue is that when I turn the key to the "on" position (not starting the car), the tach pegs at 8k. It remains that way once started and running. This seems to be indicative of a very simple problem in the electrics, but I do not know what that problem is. Does anyone have any suggestions?