So, I got my tach working and installed. If you want the play by play, here ya go
http://forums.pelicanparts.com/porsche-911-technical-forum/705064-tachometer-wiring-differences-2-7-3-0-a.html
This is the short version of what I did. I connected a wire to #12 pin of the 14 pin connector and ran that to the distributor point. Here is how I wrapped the wire around pin 12.
Here is the wire at the distributor point.
Here is the wiring at my tach. The basic wiring is:
+ = Red and Blue wires (powered only with the ignition on)
TD = Purple and black wire
- = Brown wire
I had a red wire in there as well that was constant power. Not sure what that is for, but I capped it off for now.
Before installing it, I pushed the bezel back into place. As you might remember, I took this apart to solder in a new resistor. I took a screwdriver and flattened out the bezel. Looks pretty good.
Then I put it back into the dash. TESTED EVERYTHING before putting my steering wheel back in. While I was at it, I centered my steering wheel nicely.
