1999 Chevy Silverado A/C ?

[BACKYARD88]

The actuator is a part number 52474810 list price is $74.40.
I can't say with 100% certainty that the actuator is the problem, all I can say is that it is the most common problem for the concern you are describing. Here's the replacement procedure. Whatever you do don't turn the key on with the actuator plugged in and not connected, if you do it will turn out of range and once this happens it is no longer any good. Good luck, and if you have any more questions or would like me to fax you the testing procedures and schematics let me know.

Temperature Actuator Replacement
Removal Procedure
Remove the instrument panel hush panel .



Disconnect the electrical connector (8) from the temperature actuator (9).



Remove the temperature actuator retaining screws.



Remove the temperature actuator.
Installation Procedure




Install the temperature actuator.



Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the temperature actuator retaining screws.

Tighten
Tighten the screws to 1.6 N·m (14 lb in)





Connect the electrical connector (8) to the temperature actuator (9).
Install the instrument panel hush panel.