So, my tachometer had not worked since the other day when it randomly worked for about 30 minutes. Last weekend I had to take of the air intake to work on my glow plug wiring. When I took off the glow plug wiring harness, I noticed a break in a lime green colored wire that lead to a sensor on the side of the block, located about 6 inches below where the glow plugs are. I repaired this wire, and when my work was done and I cranked the engine, guess what--the tach was working.

The next day on the way to work I was pretty pleased to watch my tach happily bounce up and down between the rpm range--fixed it seemed. But alas, when I cranked her up to go home that day, no tach...and no tach since then.

Is there any connection between the green wire and sensor on the block and the tach, or is this just another random incidence of tachometer haunting?