A/C Control - Operation of Celsium/Fahrenheit Display
90pontiac24Bulletin Number: 90-8-27
Reference Number: 008115
Publish Date: 8/90
Subject: SERVICE MANUAL UPDATE - SECTION 8A AND ESM - (OPERATION OF CELSIUS / FAHRENHEIT)
MoDels
Affected: 1988-1990 BONNEVILLE MODELS
The following information is to be added to the service manuals.
The Heater and A/C Control Assembly on vehicles equipped with Electronic Air Conditioning (C68) can be programmed to display the external and programmed temperature in degrees Celsius instead of degrees Fahrenheit when the Ignition Switch is turned to RUN. Vehicles being operated primarily in the United States should be programmed to display degrees Fahrenheit while export vehicles should display degrees Celsius.
To have the temperature displayed in degrees Celsius upon power-up, a wire connects terminal 11 of the Heater and A/C Control Assembly to ground. This wire should not be present in vehicles operated primarily in the United States.
If a vehicle is received that displays temperature in degrees Celsius when the Ignition Switch is turned to RUN, the Heater and A/C Control Assembly can be reprogrammed to display degrees Fahrenheit by removing or cutting the wire that connects terminal 11 to ground.
Be sure to tape the cut ends back to prevent shorts.