1998 Olds Intrigue vent flow issue

jt7000

1998 olds intrigue heat/ac vent flow issue. NOT dual climate!!.
Issue is air blowing from ALL vents floor dash and defrost area. I have taken out the glove box, duct shrouds, and anything i could remove under drivers side to find the actuator...there is NO i repeat NO actuator in any of those locations. It does not matter which button I push the air flow does not change it comes out of all areas. I have been trying to fix this for almost a year now! Please how do I fix this?

imidazol97

@jt7000 said:> 1998 olds intrigue heat/ac vent flow issue. NOT dual climate!!.
Issue is air blowing from ALL vents floor dash and defrost area.

The layout of the HVAC box is different from the GM car I'm used to. #4, 46, 51 are the vacuum diaphragms that move to close doors inside the box to control where the air goes. With NO vacuum from engine, the HVAC should blow air out the defroster for safety. It takes vacuum to move the mode door and temperature mix (blend) door.

18 is also listed as a valve for control, but I don't understand that it is a different shape--I think it's the electrical control for the vacuum to the various pieces using part #37, the vacuum lines. It is controlled by the dash controls.

The diaphragms have a hole on the backside and you can push in on the rubber inside that moves when there is vacuum. With the blower motor on you can move those diaphragms and see if airflow changes. Sometimes the diaphgram tears and the motor doesn't work with vacuum. See that each one reacts to changes in the control to various settings with the engine running to supply the vacuum.

One of the internal doors may have broken or stuck and now moving.
You may have problems with #46, which is the mode door that changes direction of the air through the box. #51 closes off the defroster so that air comes out the bottom for the floor or out the dash for air conditioning. #4 chooses air from outside or air from inside the car.

The first thing to do is make sure there is vacuum coming from engine into the control. The rubber pieces in the lines an crack and dry rot with heat and age. But no vacuum should mean you get defroster. You're not getting that, so something is odd about the mode door operation.

http://parts.nalleygmc.com/showAssembly.aspx?ukey_assembly=400633&ukey_make=1029&ukey_model=14626&modelYear=1998&ukey_category=19390&ukey_trimLevel=14373

Note you can click on the "enlarge picture" and get a full size diagram that can be printed.

jt7000

Thank you for the response! It has been the best information received. Have it narrowed down to as you said #46 replacing part later today. Cross fingers for me

jt7000

Thank you for the response! It has been the best information received. Have it narrowed down to as you said #46 replacing part later today. Cross fingers for me

jt7000

@imidazol97 said:
Note you can click on the "enlarge picture" and get a full size diagram that can be printed.

@imidazol97 - hi and thank you for your help and response. I did change the (#46) mode door but no change heat a/c is still coming through all vents (floor, dash, defrost) all at once with no real force. Using the defrost only (there is a button on the dash controls) it does work and with just the defrost button pushed the air ONLY comes out the defrost vent. Since I changed (#46) mode door with no change I can only figure it to be either the vacuum though air pushed through the interior vacuum line (in "reverse") works (which doesn't make sense to me) or #49 ACTUATOR. AIR CONDITIONING (A/C) Control. AIR CONDITIONING (A/C) Vacuum Control.

• Would hooking it to the computer tell me anything regarding the vacuum for this electric over vacuum system? Thank you in advance for any and all help, advice, thoughts all are greatly appreciated!