4 Wheel Drive/SUVs: 94 Sonoma S-10 4 X 4 Extended 4.3 Vortec AT Tranny, fuse box, dash lights

Question
Problem started with torque convertor not locking up intermittently. Then SES light on. Diagnostic Indicated IAC (replaced no change)and preformed tranny svc (oil/filter). Then lost second gear, idle began surging, dash lights come on when brake pushed or left turn signal is applied. Replaced speed sensor, tranny pressure switch, tranny solenoids, tranny guy says tranny is perfect mechanically. Now lost first unless manually placed down in first. Replaced Computer (new diagonostic said quad drive solenoid) no change after new computer. Checked wiring harness visually at stereo, brake pedal switch, light switch, heater switch and all looked good. Any suggestions on where I should look for this presumed short?

Answer
The quad drive solenoid and a short in the tranny is the cause of your problems. When this happens it will like you have said, affect all your systems. Inspect all the wiring to and from the tranny, and out of the fuse box. Get back to me if not found.