FYI
The MT2500 needs list for OBDI GM stuff is fairly small
You need;
The handheld red brick MT2500.
MT2500-1099, 1980-1999 Domestic Primary Cartridge
MT2500-1193, 1980 1/2-1993 GM Primary Cartridge ( The 1999 cartridge neutered 1990 and prior support )
You don't need the fast track troubleshooting cartridges. Nice to have but unnecessary.
DO NOT put more than one primary cartridge in the tool.
Data cable ( I would buy a new 6' or 10' data cable rather than use a janky beat to hell 30 year old cable )
MT2500-10, GM-1, 12 terminal ALDL adapter
MT2500-90, MULTI-1, data adapter
**Don't worry about the GM-3 ABS & GM-2 1980-82 five terminal ALDL adapters. They cost way more than a Multi-1.
Power cables for GM & some Ford EEC III & IV; ( You can make both of these )
MT2500-100, Cigarette lighter plug to 5.5x2.5mm DC barrel plug centre positive
MT2500-200, Battery +terminal clip to 5.5x2.5mm DC barrel plug centre positive
**NOTE You don't need to run the ground to the outer contact for the mt-2500 but you will to power a Solus Pro or Modis handheld.
Ford & Chrysler need the MT2500-41 ground cable to talk to some controllers but GM always has ground in the ALDL port. You can make one with 10' of black wire, an alligator clip, clear heat-shrink, and a 12129493 Female Metripak 280 terminal.
For 1995 - 1999 vehicles
MT2500-46B, sixteen terminal OBDII adapter with personality key slot
I use a 3' OBDII extension cable with this adapter.
Keys for the 1999 Domestic cartridge;
GM uses K-2A, K-9, K-12
Ford uses K-2A
Chrysler/Jeep uses K-7 & K-13
Personality Key charts thread. Solus and Modis charts are in this thread as well.
MT2500 are based on 1995-1999 domestic primary cartridges
Snap-On personality key charts forum thread
The data cable and OBDI / OBDII adapters and some of the personality keys will work with the Solus Pro or Modis models
See the charts in the key chart thread.
For 1992-2001 GM T400 trucks I'd recommend a clone Tech2.
The MT2500 will do in a pinch but it will not do things like ABS bleed on the Kelsey Hayes ABS units.