Alternative mpg computer retrofit

[nowhhs]

I've been looking through old posts for information regarding alternatives to a Scangauge, since my car is OBD1, and the mpg version of the superMid doesn't seem to be making any progress. I've tried the soundcard in the laptop method and I wasn't able to get anything usable, just a lot of wildly fluctuating numbers. Then I found Bobski's excellent installation of the 88 Legend computer and decided to try that. While I was at the junkyard this morning, I didn't find an acura, but did find one out of an '89 Lebaron which looks like it should work. My question: does anyone have a shop manual with an electrical diagram for that year (approximately) Dodge, Chrysler, or Plymouth that could tell me where the 9 wires connect? When I pulled it all the wires went directly into a very large taped harness so I couldn't trace them. If I can get this working, I'll do a write up with photos if anyone else is interested. Thanks in advance, Norm