heater stopped working

[Jizzle188]

On my 1998 Chev 1500 Silverado my heater stopped working. The fan still blows air into the cab though along with adjustments from low to hi. The fan only blows cold air through the windshield area instead of directly to you or your foot area and remains like that when I try and change it. The heat stays at one temperature when I try to adjust the temperature. It seems like it happened after I let the heater blow the hottest air it could for about an hour. Can anyone help me out?

[Bigg G]

I had the exact same problem on my 03 Chevy Astro. The door in your heater box is not opening to let the warm air in to your vents. After letting the truck run a bit turn off your engine but leave the switch in the on position. Slide or turn your heat / AC control lever from from the vent to the defrost position a few times while listening for movement in your heater box just below your dash in the center. You should hear it opening and closing. If you don't there's a pretty good chance you have a bent control cable (if you recently removed or installed your radio) or a cracked vac line.

[Jizzle188]

Originally Posted by Bigg G

I had the exact same problem on my 03 Chevy Astro. The door in your heater box is not opening to let the warm air in to your vents. After letting the truck run a bit turn off your engine but leave the switch in the on position. Slide or turn your heat / AC control lever from from the vent to the defrost position a few times while listening for movement in your heater box just below your dash in the center. You should hear it opening and closing. If you don't there's a pretty good chance you have a bent control cable (if you recently removed or installed your radio) or a cracked vac line.

Infact I recently did take out my deck a few times...

[Jizzle188]

still having the same problem. Anyone have any other suggestions?

[J-Ri]

The air going only to the windshield is most likely a vacuum supply problem. The actuators will default to defrost position if there is no vacuum. This is so you won't fog/ice up if the system does fail.

The temperature is done with a cable. Follow the cable from the temperature control to the blend-door. If it is attached on both ends, disconnect it from the blend-door side and move the door by hand. You should be able to hear and feel it when at it's range of movement.

[Jizzle188]

is the vacuum and blend door located under the hood? I have no idea where to look. I will try to fix this problem myself as I am low on cash and I hope to find this problem and fix it.

[2000CAYukon]

Originally Posted by Jizzle188

is the vacuum and blend door located under the hood? I have no idea where to look. I will try to fix this problem myself as I am low on cash and I hope to find this problem and fix it.

The actuator for the blend door is electric and does not use vacuum. On my 90, I had to remove the glove box and the tape deck (middle of the dash) to replace it.

//2000CAYukon

[Jizzle188]

Does anyone know if the actuator is down around the foot area between the driver and passenger in my 98?

[Jizzle188]

Found the actual problems. It turned out to be the actual heater and vent control. Thanks for trying to help everyone...