Auto Check Problems in a 91 200TQ

[Russ Southerlin <a911sc@yahoo.com>]

All,
Brother-in-laws 91 200TQ Auto Check system is dead. The dash disply does
not do anything, even with the ignition key on and engine off.  The
thing is chiming occasionally as the car is driven.

I had the instrument cluster out once before looking for bad connections
or broken solder etc. Cleaned up the connectors and put it back
together  and it was improved for a while but now it is dead.

Could this be a bulb or bad connection?

Where is the Auto Check computer located?

TIA
Russ
87 5KTQ
Littleton, CO