1993 GMC SIERRA Electrical Systemignition Problems

I PURCHASED A 1993 GMC SIERRA PICKUP FOR MY SON FROM MY FATHER WHO WAS THE ORIGINAL OWNER. MY FATHER TOOK VERY GOOD CARE OF IT MAKING ALL SCHEDULED MAINTENANCES AS WE HAVE DONE AS WELL AFTER PURCHASING IT. MY SON WAS ON HIS WAY TO SCHOOL WHEN ALL OF A SUDDEN THE STEERING COLUMN BROKE. HE WAS UNABLE TO STEER THE TRUCK AND HAD TO COME TO A COMPLETE STOP AFTER GOING APPROXIMATELY 50 MPH. LUCKILY HE DID NOT LOOSE CONTROL NOR DID HE CRASH HEAD ON INTO THE ON COMING LANE OF TRAFFIC. ONCE STOPPED HE COULDN'T GET THE IGNITION TO TURN OFF WITH THE KEY. HAD TO JIGGLE THE STEERING COLUMN AROUND TO SHUT OFF THE ENGINE. HE DID THIS WITHOUT THE KEY IN THE IGNITION. WE HAD THE TRUCK TOWED BACK TO OUR HOME AND ARE IN THE PROCESS OF FIXING IT. *TR

1) DASH BRAKE LIGHT CONSTANTLY ON OR FLASHING, CODE = SHORTED ABS DEFECTIVE? 2) 4WD TRANSAXLE- SHIFTER FORK AND THRUST BEARINGS BROKEN. NO FORWARD OR REVERSE ON HIGHWAY-VERY DANGEROUS BREAKDOWN 3) ECM ELECTRONIC CONTROL MODULE FAILURE, PREVENTING THE 3-4 OVERDRIVE SHIFT IN THE TRANSMISSION-VERY HIGH RPM UNDER LOAD. 4) AUTOMATIC TRANSMISSION, NO REVERSE DUE TO LOSS OF PLANETARY GEAR SET (2) DUE TO DEFECTIVE WORKMANSHIP (DRIFT PIN SETTING GEAR IN HUB HAD WORKED OUT THEREBY GALLING AND MILLING OUT THE HUB AREA=LOSS OF PRESSURE AND BEARING STABILITY. 5) NYLON ROCKER ARM RETAINERS HAD FRACTURED AND BROKEN DUE TO DEFECTIVE MATERIALS, ALLOWS ROCKER TO FALL OFF ROCKER ARM SHAFT AND PUSH RODS TO FALL INTO CRANKSHAFT...ABRUBT ENGINE HALT AT HIGH SPEED...VERY DANGEROUS. 6) GLOW PLUG CONTROLLER DOES NOT ACTIVATE THE GLOW PLUGS AFTER HOT ENGINE SITS FOR ABOUT 15 MINUTES...ENGINE WILL NOT START. *AK