Lack Of Air Through Front Vents

[Rexfordray]

Just purchased and installed a new Heater/Air Conditioning Control unit for my 1980 Fleetwood 2 Dr Coupe from USAPartsSupply.Com. I had a problem with the blower motor sometimes not coming on at all or there was a unrealistic amount of time delay before the blower motor will activate. Further, no air would blow through the front dash vents. Again, sometime yes but more often than not, no. I installed the new Control Unit with no problems. It is a fairly simple installation. But now, I still have no air coming through the center dash vents. I have located a part that is called an "Air Door Actuator Motor that apparently pushes a lever that forces the center dash vents to open. I can manually push on the lever this is controlled by the motor and I get good cold air through the vents. Is it safe to say that the Air Door Actuator Motor is bad? I have located one from a 1978 Fleetwood and it appears identical to the one in my car.

UPDATE: Just completed installation of the Door Actuator Motor and still no effect on the front dash fents. After installing the replacement door actuator motor I can see that it opens and closes a flap that closes the hot air for the A/C to cool and closes the A/C for the heat to work.

Still nothing through the center dash vents.

Any ideas anybody? I'm not sure what to do next.

Thanks, Rex from Pensacola, FL.

Wish I could send you pictures of this car....it is a beauty. I have spent over $8,000 since August this year on restoring the car. It is a passion of mine to understand the technology of these old Caddys still have technology you still don't see some new cars (i.e. climate control, crusie control, 6-way power seats, power mirros, etc.) all this is standard equipment on a car which now is 27 years old...can you image that in 1980?

[Ranger]

If I am understanding you correctly, the side dash vents work, but not the center? That would lead me to think that the ducting is closed or disconnected somewhere.

[Rexfordray]

If I am understanding you correctly, the side dash vents work, but not the center? That would lead me to think that the ducting is closed or disconnected somewhere.

If I am understanding you correctly, the side dash vents work, but not the center? That would lead me to think that the ducting is closed or disconnected somewhere.

Dear Ranger...the point is that I can't get air to come through my dash vents after replace the Heater/Ac Control unit with a brand new one and the Door Actuator Motor.....I get plenty of heat and A/C but it's going directing to the floor floors and not the das vents. Help! I'm just at a loss.

I have located the primary vacuum source on the intake and now attempting to flow where it goes.

I am not smart enought to determine that if I put the A/C on, that obviously I get cold air but why is it that I have nothing through the dash vents. Could it be that I have a bad Door Actuator Motor because it controls the transfer from heat to A/C and visa-versa and perhaps there is a separate vent connection on the door Actuator Motor that forces open the center dash vents...I'm just not knowledgeable on this. Anyone out there that could advise me?

Please!

Thanks,

Rex from Pensacola, FL

[mmarinov]

Dear Ranger...the point is that I can't get air to come through my dash vents after replace the Heater/Ac Control unit with a brand new one and the Door Actuator Motor.....I get plenty of heat and A/C but it's going directing to the floor floors and not the das vents. Help! I'm just at a loss.

I have located the primary vacuum source on the intake and now attempting to flow where it goes.

I am not smart enought to determine that if I put the A/C on, that obviously I get cold air but why is it that I have nothing through the dash vents. Could it be that I have a bad Door Actuator Motor because it controls the transfer from heat to A/C and visa-versa and perhaps there is a separate vent connection on the door Actuator Motor that forces open the center dash vents...I'm just not knowledgeable on this. Anyone out there that could advise me?

Rex:

I had a similar problem on my '81 Pontiac years back. I seem to recall replacing the control unit and then finding the real reason was vacuum-related. I'll see if I can jog my memory with old receipts, etc.

Mark

[Ranger]

Well ,you said "Still nothing through the center dash vents" so I wasn't sure if you were getting nothing from the dash vents at all or just the center ones. Without the help of a FSM I am not sure how the '80 system is set up. Is there a tempurature control valve in the coolant line under the hood that controls how much coolant is allowed through the core, as I remember from the "old days", or does coolant constantly flow through the core like current models and tempurature is controled by an air mix door? What I am getting at is if you have an air mix door, then you may have the wrong acuator as there would be another mode door (air distribution door) controling air flow to the defroster, dash vents and floor vents. In rereading post #1, it sounds like you are talking about an air mix door. The mode control door should be farther down stream. Hope this is of some help. Check Ebay, you may be able to find a FSM by Helm Inc. I would not bother with Chiltons or Haynes.

[Rexfordray]

Dear Ranger...the point is that I can't get air to come through my dash vents after replace the Heater/Ac Control unit with a brand new one and the Door Actuator Motor.....I get plenty of heat and A/C but it's going directing to the floor floors and not the das vents. Help! I'm just at a loss.

I have located the primary vacuum source on the intake and now attempting to flow where it goes.

I am not smart enought to determine that if I put the A/C on, that obviously I get cold air but why is it that I have nothing through the dash vents. Could it be that I have a bad Door Actuator Motor because it controls the transfer from heat to A/C and visa-versa and perhaps there is a separate vent connection on the door Actuator Motor that forces open the center dash vents...I'm just not knowledgeable on this. Anyone out there that could advise me?

Rex:

I had a similar problem on my '81 Pontiac years back. I seem to recall replacing the control unit and then finding the real reason was vacuum-related. I'll see if I can jog my memory with old receipts, etc.

Mark

Dear Ranger...the point is that I can't get air to come through my dash vents after replace the Heater/Ac Control unit with a brand new one and the Door Actuator Motor.....I get plenty of heat and A/C but it's going directing to the floor floors and not the das vents. Help! I'm just at a loss.

I have located the primary vacuum source on the intake and now attempting to flow where it goes.

I am not smart enought to determine that if I put the A/C on, that obviously I get cold air but why is it that I have nothing through the dash vents. Could it be that I have a bad Door Actuator Motor because it controls the transfer from heat to A/C and visa-versa and perhaps there is a separate vent connection on the door Actuator Motor that forces open the center dash vents...I'm just not knowledgeable on this. Anyone out there that could advise me?

Rex:

I had a similar problem on my '81 Pontiac years back. I seem to recall replacing the control unit and then finding the real reason was vacuum-related. I'll see if I can jog my memory with old receipts, etc.

Mark

Dear Mark,

Last evening I was talking to a mechanic and he told me to look for the followng:

First, go back to the new cntrol head and pull of the pod of vacuum hoses (there are 6 hoses that join together with a rubber boot connector on the rear of the control head) and be sure there is vaccum coming to the head. Secondly if there is, then look for a servo that pushes the center vents out to allow air...(be sure there is vacuum coming to it and if there is, the servo is bad. This servo is under the dash around the sterring column. Thirdly, if all this is good, then there is a plastic cover assembly to the rear of the control head that actually hoses the vent flap for the center vents...(loosen the bolts on the side and raise the cover up encought to manually push the flap...it could be that it is just stuck in which case job the hinges.

I'll keep you posted and if anyone else has any ideas, please let me know. I'm kinda at the "end of my rope here" so to speak.

Thanks Again! Rex from Pensacola, FL.

[mmarinov]

Dear Mark,

Last evening I was talking to a mechanic and he told me to look for the followng:

First, go back to the new cntrol head and pull of the pod of vacuum hoses (there are 6 hoses that join together with a rubber boot connector on the rear of the control head) and be sure there is vaccum coming to the head. Secondly if there is, then look for a servo that pushes the center vents out to allow air...(be sure there is vacuum coming to it and if there is, the servo is bad. This servo is under the dash around the sterring column. Thirdly, if all this is good, then there is a plastic cover assembly to the rear of the control head that actually hoses the vent flap for the center vents...(loosen the bolts on the side and raise the cover up encought to manually push the flap...it could be that it is just stuck in which case job the hinges.

I'll keep you posted and if anyone else has any ideas, please let me know. I'm kinda at the "end of my rope here" so to speak.

Thanks Again! Rex from Pensacola, FL.

Ah yes, you're bringing back memories...I remember the multi-colored lines and tracing them back to something...don't remember if it was a leaking line or bad servo though.

Just had to replace the servo for my parking brake - that was fun to access!!