Im Stumped!

[ronster70]

I have a 1998 GMC sierra 1500 4X4, Im going to describe this the best I can so please bear with me... When I start my truck in the morning, EVERYTHING works fine, meaning, I can switch the heat from defrost to the floor to vents, wherever I need it, it blows out stong no matter where I put the selctor, but when I drive truck for about 10 to 15 minutes ALL air flow stops, there is no air flow coming out from anywhere but the fan is blowing! Im very stumped! I cant figure this out, Ive checked the blend door actuator and thats fine. Any help would be greatly appreciated!!!!

[Easytide]

I have a 1998 GMC sierra 1500 4X4, Im going to describe this the best I can so please bear with me... When I start my truck in the morning, EVERYTHING works fine, meaning, I can switch the heat from defrost to the floor to vents, wherever I need it, it blows out stong no matter where I put the selctor, but when I drive truck for about 10 to 15 minutes ALL air flow stops, there is no air flow coming out from anywhere but the fan is blowing! Im very stumped! I cant figure this out, Ive checked the blend door actuator and thats fine. Any help would be greatly appreciated!!!!

 

 

Plugged up cabin filter?

[ronster70]

I have a 1998 GMC sierra 1500 4X4, Im going to describe this the best I can so please bear with me... When I start my truck in the morning, EVERYTHING works fine, meaning, I can switch the heat from defrost to the floor to vents, wherever I need it, it blows out stong no matter where I put the selctor, but when I drive truck for about 10 to 15 minutes ALL air flow stops, there is no air flow coming out from anywhere but the fan is blowing! Im very stumped! I cant figure this out, Ive checked the blend door actuator and thats fine. Any help would be greatly appreciated!!!!

 

 

Plugged up cabin filter?

 

 

Where is the cabin filter???

[jblakeney]

Can you hear the fan? If so its an actuator (door or motor). Something has to be stopping the air flow. It should at least come out somewhere.

 

Jbo

[Easytide]

I have a 1998 GMC sierra 1500 4X4, Im going to describe this the best I can so please bear with me... When I start my truck in the morning, EVERYTHING works fine, meaning, I can switch the heat from defrost to the floor to vents, wherever I need it, it blows out stong no matter where I put the selctor, but when I drive truck for about 10 to 15 minutes ALL air flow stops, there is no air flow coming out from anywhere but the fan is blowing! Im very stumped! I cant figure this out, Ive checked the blend door actuator and thats fine. Any help would be greatly appreciated!!!!

 

 

Plugged up cabin filter?

 

 

Where is the cabin filter???

 

just below the gove box,between the blower assy and the evap assy there is a 1" wide pastic strip..one screw..tilt that down and filter is in there,,,