OBD2 Scanner "LINK ERROR"

My 1998 Montana won't start. The fuel pump won't kick on altho jumping it
with a + wire it will kick on. No spark on the spark plug wire. I have a spare computer and installed it but with same results. Hooked up my OBD2 scanner
and after a few seconds it prompts a message "LINK ERROR". Now I tried and
tried but still says "LINK ERROR".
Now, this happen after about 3 times when the van wouldn't start. after wiggling the wires underneith the back of the drivers side it started. Just after fixing it I decided to crank it up one more time just to make sure and it wouldn't start.
What is the fix for a "LINK ERROR"? Where do I look? What do I look for?
What other diagnoses I could make?
I must admit, I really got sold a bill of goods. Never in my life time did I ever
own a vehicle with so many problems.
Now I enjoy fixing things that are broke, but things are tough for me economically and health wise.
If anyone out there have an idea on how to fix this and get my car working again I will surely appreciate it.
Other problems: cruise control, DIC overhead display, air pump (rear),
door locks, drivers side pwr windows, tachometer, abs,
tcs, h2o level.

Each one started failing in 3 week intervals starting with first the tachometer, the air pump,cruise control,DIC, door locks, pwr window, abs
then tcs then h2o level and of course now the fuel pump, ignition, and computer.

But tell me, is there a web site where one can down load a " Service Repair
Manual" (complete with wiring diagram).

Sounds like you have bad connectors on the harness. Maybe instead just a loose ground somewhere. Can you give more detail where the wires was or coming from that you wiggled to get it to start. Was it there at the plug going into the ecm?

Go to advance auto or autozone and look for a Haynes manual for your vehicle.

Thank you for your prompt reply. I did get underneith and wiggle the wire to the ECM or the connector for the scanner. There must be alot of grounding points.I checked a as many as I could see, but nothing seems to work. It's like trying to get from brooklyn,ny to manhattan without a road map...I mean, one gets lost with wires running every which way, all kinds of colors and sizes. Oh by the way, I do have a Haines repair book but it doesn't much about anything. What I like is to download a
Service Repair Manual. A good one would have about 7gigs of total info.
If you know of a site, please feel free to email me.