I'd love to get a copy of the gauge schematics if you ever find one.
The part number for the gauge module is 124 542 43 01. The only schematics I have is for the whole cluster P/N 124 542 12 69 and not for a specific gauge. It kinda helped me find my way around to power the unit on the bench to perform the calibration without having to keep plugging it back and forth in the car ... Let me know if you need to take a look at the schematics I have and I can send you email with it... as soon as i find the soft copy. By the way, do transistors come in a resister-like form? Meaning do they have color bands etc? The 49.9 ohm resister had about five color bands, and then i took it off and measured it and took it to parts store and they confirmed it was 49.9 fixed value resister.