Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

HVAC Temperature Control and Output Selection Repair

This is in regard to a 2000 Chevrolet Silverado 1500 with the 4.8L engine. This is the basic model, sold to fleet customers. It has approximately 209,000 miles on it.

The problem is that no matter what position I set the temperature or output vent dials, all I get is maximum heat out of the two vents on the side of the dash (facing toward the doors). Even if I turn the A/C on, it makes no difference. The A/C system has refrigerant, and the compressor runs, but no cold air.

I have read online about a “blend door actuator” repair, but could not locate any decent instructions. I have a Haynes book, and it does not have any instructions for this repair. Any advice, or link to a website or discussion board with good instructions for this repair would be appreciated.

A blend door actuator regulates whether the air is cold or hot, or in between when coming out the vents.

A mode door actuator regulates if the air comes out the defrost, dash vents, floor, or a combination.


There are lots of Youtube videos on locating and replacing these actuators. Tester posted one. Searching will get you more. Cheap actuator, Pain in the back to replace them.

The blend door actuator motor should be located directly “above the hump”

You do NOT have to tear the dash apart to replace it

yep. Just did one in my truck on Friday. pretty simple, but have a 7/32’s short socket handy before you start. you’ll need it to get the actuator off.

The mode door actuator is up under the dash, and it more difficult to get at, but not impossible. more of a pain to get it positioned properly while doing your best contortionist impersonation… lol

Sounds like you may have both bad.

1 Like

The lower dash was removed so he could film the procedure!