multtiple malfunctions occur when A/C or heater is turned on, Details below?

Question

Background info: 1998 Pontiac Grand Am. When knob is turned from OFF to any other position the A/C or Heat comes on. The fan speed control knob is a separate knob and it does not have it's own OFF setting-just low-to-high variable settings so the turning the airflow position switch from OFF to any other setting causes the air to flow automatically.
The Problem: Turning this system on causes all of the dash indicator lights to come on(Oil,Engine,Brake,etc.). Additionally, the gear shifter will not come out of the Park position. The person who own's the car has been replacing a '20' fuse in the under-the-hood fuse box. The fuse that is being burned and replaced everytime this happens is the center, aft-most fuse-(furthest from the bumber,closest to the driver, middle fuse of 3 fuses on that aft-most row). OBD-II codes showing are: P- 753 & 758(shift solenoid 'A' & 'B' circuit electrical), 740-I have this one covered, 1665-n/a,1676-n/a, & 1860- TCC PWM solenoid CKT electrical. pls help.

Answer 1

You have a short in the dash or the dash circuit board behind the guages. Requires some detailed investigation and experience to solve. If you don't possess that experience I highly recommend you find a good mechanic as some shops will charge you an outrageous fee to locate and fix something that can be relatively simple to diagnose and repair by a qualified experienced mechanic..