Mitsubishi Repair: 1992 gallant computer codes, advanced auto parts, factory service manuals

Question
is there a book that tells you how to read the computer troubleshooting codes for a 1992 4 dr mitsubishi gallant vin # ja3cr56vinzo47980

Answer
Ann,
A company called Chilton's does make a repair manual for your car.  There is a good chance it has troubleshooting codes in it for you.  It's not too commonly sold in stores, but you can check PepBoys, AutoZone, and Advanced Auto Parts if you have any of those stores in your area.  If not, it's also available online:
http://www.delmarlearning.com/Browse_CatalogDetail.asp?XXID=11995&ISBN=080199315...

The ultimate manual you can buy for your car would be the factory service manual; available to order from any Mitsubishi dealership.  Typically, the factory service manuals are a bit more expensive, but they can get you the exact manual that the Mitsubishi engineers developed for you particular car.
Good luck!