inop tachometer/need new tach?

[AUDIJIM at aol.com]

I made some great observations yesterday. After I re-soldered every contact 
on the instrument cluster (IC) boards, the Tach was again inop. But it was 
actually working correctly for two or three days until yesterday. Why? I don't 
know. I found that if I pull the hand brake (emergency brake) and the "Brake" 
light indication illuminates on the cluster, the Tach works. If I release the 
hand brake, the Tach stops working. I usually do not use my hand brake, but I did 
this time. All I have to do is trip the hand brake switch, the light comes 
on, and the Tach starts working. Today after work, I got in my car, took it out 
of gear, started it in neutral and my foot on the brake and the low oil 
pressure graphic came on and the Tach stopped working. As soon as I pulled the hand 
brake, the low oil graphic went away and the Tach came back to life. So I'm 
getting somewhere! So I have a hard case for my sunglasses that when positioned 
under the hand brake lever, it just lifts the lever up enough to trip the 
switch and the brake warning light comes on, but not enough to drag the parking 
brake on the rear calipers. I'll play with this in the wiring diagram tomorrow.

Jim