Remove the dash assembly to gain access to the blend door actuator.
The heater blend door is not run by vacuum. It is run by an electric actuator.
The blend door actuator can go bad. Big job to replace it. Dash assembly must be removed to gain access to it.
It does not use a cable. The heater blend door is operated by a electric motor. The complete dash assembly needs to be removed to gain access to the unit.
The temp blend door actuator is probably at fault.
Control problem, blend door not working are the places to start
You will need to remove the dash assembly to gain access to the blend door actuator. Recomend purchasing a shop manual of you intend on doing that job.
It is located behind the dsah assembly, attached to the HVAC assembly. You need to remove dash to gain access to it.
On the HVAC box behind the dash assembly. Unfortunately, the dash has to be removed to gain access to it.
The heater temp blend valve is located behind the dash assembly. The dash assembly must be removed to gain access.
To replace the blend door on the rear AC of a 1998 Chevy Venture, start by removing the rear AC unit from the vehicle. This typically involves taking out the access panel and disconnecting any electrical connectors and ducts. Once the unit is out, you can access the blend door and replace it with a new one. After installing the new door, reassemble the AC unit and reconnect everything to ensure proper function.
Yes it could and so could a stuck open thermostat or a plugged heater core or a faulty temperature blend door actuator.
Changing the heater temp blend door actuator requires removal of the dash assembly. Big Job. You will need a shop manual to attempt that one.