OK i have a '93 Galant of my girlfriends that I am trying to wire. This is what I found that helped me out the most. Go down to Chrysler/Mitsubishi Joint and it will show you the color in the dash...and the Modern harness color. http://www.installdr.com/Harnesses/DCP-Wiring.pdf That helped me alot. Only problem its says is not to use the illuminator or dimmer wires.
You can get a distributor's wiring diagram for a 1995 Galant online at places like The Galant Center. You can also find the diagram at Mitsubishi Motors.
You can find a wiring diagram for your 1988 Mitsubishi Gallant at most Mitsubishi dealerships. Mitsubishi service manuals will have the wiring diagram and can be found at most local libraries.
for a stereo? go to the12volt.com
clubvr4.com
go to __the12volt.com __aojedam
http://www.installdr.com/Harnesses/Mitsubishi-Wiring.pdf
go to installdr.com to see how to remove and install a stereo out of any car
Chilton's repair manual (about $20.00) has all the wiring diagrams for your entire car.
Go here: http://free-pdf-ebook.com/2007/11/04/mitsubishi-pajero-1994-wiring-diagrams/
The stereo wiring diagram for a Ford is a drawing showing the wiring placement for the stereo. The diagram will be different for various cars and trucks.
This website has a lot of wiring for many cars including '92 Eclipse. http://www.modifiedlife.com/1992-mitsubishi-eclipse-car-audio-wiring-diagram/
http://www.the12volt.com/installbay/stereodetail/1541.html