No defroster?

CHRISTOPHER WALLAKER

MEMBER
2000 CHEVROLET SILVERADO
5.3L
V8
4WD
AUTOMATIC
195,000 MILES

There had been a clicking noise coming from the dash, I believe lower passenger side. Today I have heat coming out of the vents, but when I switch to defrost it stays blowing out the vents. The light for recirculate goes out when I switch from vent to defrost, so I assume the switches are fine. Where to start? Blend door on pass side? Truck is base model, rubber floor, 8ft bed ect.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Hi,

If the airflow direction won't change to defrost, the mode door is the likely cause. The mode door is operated by an electrical motor. If you hear a clicking, chances are the plastic gear in the actuator is missing a few teeth.

I attached the directions below for the removal and replacement of the actuator. Before you purchase one, locate the actuator under the dash and see if you can feel it or tell if that is where the clicking is coming from. If you can't tell, remove the actuator and see if it responds to the defrost request. Place a light load on the gear and see if it skips.

Let me know what you find or if you have other questions.

Take care,

joe

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Tuesday, December 13th, 2022 AT 9:59 PM

CHRISTOPHER WALLAKER

MEMBER
2 POSTS

So, I drove the truck for a while, and all of a sudden, I heard the vents switch to defrost very slowly. I moved the switch to vent, and after about 45 seconds it switched slowly to vent, I switched it back to defrost, and about 45 seconds I went back to defrost, which is where I need it to be right now. It's been in the teens in the evening, and freezing fog and snow during the day. You think I still need to replace this part, or is there something I can clean and degrease? Also, can I get away with an amazon part? Truck has nearly 200,000 so who knows how long it will even be on the road.

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Tuesday, December 13th, 2022 AT 10:12 PM

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Chances are the actuator is just getting tired. If you want to, you can remove it and clean things, and make sure it is moving easily.

Let me know.

Joe

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Wednesday, December 14th, 2022 AT 8:39 PM