Diesel Bombers - Does a 1990 W250 have a PCM?

Just bought my first Dodge Diesel... a less than shiny 1990 W250.
Its a bit rough around the edges, but I'm looking forward to spending some quality time under the hood.
Anyway, the prior owner had a full lineup of gauges installed (boost, pyro, AT temp), they light up, but none of them are working. I also noticed the speedo only works intermittently, no odometer, it shifts a little rough, and until i spun the fuel pin and turned the star wheel, it was pretty gutless. That last issue might not be related.
From what I've read so far this sounds similar to later years (91 and up) PCM issues, but in searching here and other places I can't find whether the 90 W250 actually had a PCM or not. There doesn't seem to be a part available either. So if there isn't a PCM to be bad, any ideas on what might cause these symptoms?

Thanks