PLEASE HELP!!! BCM? vacuum lines?

[Rio]

please help. I finally got the air to blow in my car. However, the air only blows out of the windsield defrosting vents on the top of the dash. No matter what it is set on (ex. panel-floor) it will still blow towards the windshield. I ran the codes and it came back 888. So, everything that this self-diagnostic test checks is cool. But, what could cause this problem? I can control the speed of the blower, so I guess the blower control module is fine. Is it the actuator? is it the vacuum lines?

When I change where I want the heat to be released (ex. panel-floor) I can hear something behind the dash. It sounds like vents or doors closing or opening behind the dash. Still, the heat/air only comes out on the top of the dash towards the windshield. What could cause this problem???

Thanx guys... frown

 

[projectSHO89]

Need to know what year car you have. Always. Put it in your sig along with your tranny, if not evident.

Your system has defaulted to the no-vacuum position of DEFROST only. This may be due to several things:

1) Loss of vacuum sorce from intake manifold. Check the vacuum line that goes through the firewall at the heater core inlet/outlet area. make sure it isn't disconnected from the manifold. Do you hear a hissing sound when pressing any of the buttons on the EATC (engine running)? If yes, you have vacuum at the control head. If no, vacuum is missing.

2) There are two vacuum motor operated doors behind the center of the dash (another behind the glove boxe for RECIRC). The blend door for control of the temperature of the air by controlling the flow of air through or around the heater core is an electrical motor. One vacuum motor controls the airflow between the floor and the vents. The other one is the Defrost/panel motor that directs airflow to the panel when activated. These motors are set so that if there is no vacuum, you get all airflow through the defroster for safety.

3) There may be a fault in the control head so that there is no control of the individual vacuum lines that go to the motors.

You really need the manual to troubleshoot this. Too many variables to check without it.

Steve

 

[Rio]

1993 ATX...

 

[projectSHO89]

Go get the manual, start troubleshooting.

Steve

 

[pjtoledo]

Behind the glove box is a green plug with some vacuum lines. The black one is vacuum coming from the engine. I have the plenum assembly from a 93 ATX downstairs, just looked for the floor/defrost selector. It isn't there, must be in the dash instead of in the plenum assembly.

Perry Toledo,Ohio