Tach on '85 300D CA model doesn't work

[kaskillah]

The tachometer on my '85 300D with California emissions model does not work. I found the elusive fuse behind the glove box but when I would put in a good fuse, the tach will work but then for some reason the transmission will not shift normally and sometimes not even shift out of first gear. My CD manuals are of no help nor is the transmission manual. I have tried posting this problem on other MB forums but they were of little help other than finding the fuse. The CA model is different from the Federal version and the connector on the left fender well does not contain the tach controller. I am hoping there is someone in this forum that may have the answer. I don't want to take it to the dealer because I can't afford their sky-high rates and there are no independent MB garages in my area.
Thanks in advance!