As mentioned earlier, I got an instrument cluster yesterday with the tach. Armed with Jim Thompson's write up on how to install I head out to the driveway. First thing I find is the plug to my current instrument cluster ('85 Weekender) matches the one with the tach-sweet! Plug and play? No, not that easy. Plug in the new cluster and fire it up. No gas gauge, no temp gauge, tach is dead. Everything else works. Pull it back out to find someone had taken the voltage stabilizer off the new cluster. Swap in the one from my old one and I now have fuel and temp, plus now a constantly blinking coolant light. Tach still dead. Run a wire from the neg side of the coil to the green on the harness and now the tach works. So, I go to put everything back together and......on the left side of the housing the framework (for lack of a better term) that holds the headlight switch and seat belt/brake warning lights in place is GONE! I didn't even realize this piece was removable-tried to get the one of my old cluster and managed to break it, but not so bad that I couldn't reuse it. So, now I have a tach, temp gauge, fuel gauge and a constantly blinking coolant light. Oh, one more thing, I also scored a "99" relay from a Jetta so I know have true intermittent wipers . 

Jeff Stewart