Hi ColdNorth,
I don't know if you've been following my posts in the Quest for Accurate Gauges thread, but my gauges have been dead for 2 years. It turns out there were 3 glass fuses under my dash. One on a black wire is a negative line, one is on a red wire with a yellow push connector which is power into the MDC. The third is on a purple line with a yellow push connector, which is the fuel data sender. I replaced these with both yellow push connectors with ATC inline fuseholders for the blade type fuses and used 3A blade fuses and my gauges now work. I'm guessing the 3amp fuse which is as thin as a human hair is to protect the MDC. It is more like a computer fuse than one for a car or boat. I couldn't find the original fuse size and amperage even at AutoZone, Advance Auto or even Radio Shack, so that's why I replaced the fuseholders.
HTH,
bmccalla