: 67 Coupe DeVille AC issue



aceuh
08-20-10, 08:26 PM
Hey guys. I just bought a 67 Coupe DeVille and I'll be the first to admit I'm pretty green as far as Vintage Cadillacs are concerned. I've owned my share of Impalas, pickups, jeeps, camaros and ....well you get the picture. But this is my first Cadillac.

When I turn on the A/C it takes it a few minutes for the blower motor to start working. Proabably about a half mile of driving...or four or five minutes of idleing. Once it starts to blow it comes out the center vent excellent but there is very little airflow out of the side vents. I've already pulled the ducts from the plenum to make sure that they weren't blocked...which doesn't seem to be the case. Air is coming out of either side of the plenum and its cold...the volume/intensity just seems to be lackluster.

Once the car has warmed up, I can cut it off and let it sit for a few minutes...and when I crank it back up, the blower works immediately.

Any tips, advice, pointers would be gfreatly appreciated guys!

Thanks

jayoldschool
08-20-10, 09:25 PM
When I turn on the A/C it takes it a few minutes for the blower motor to start working. Proabably about a half mile of driving...or four or five minutes of idleing.

This is normal operation, I believe. Other members note that on the later models you can get it going right away by turning on the defrost then switching back to AC.

aceuh
08-21-10, 12:30 AM
This is normal operation, I believe. Other members note that on the later models you can get it going right away by turning on the defrost then switching back to AC.

Gotcha!....Anyone have any suggestions about the lack of airflow in the vents closest to the doors?

Garys
08-21-10, 02:26 AM
Congratulations on your purchase! The ac system on these cars are activated by a vacuum switch. Any leak in vacuum, I mean any, will effect the way the system operates. Jayoldschool is right about moving the lever to defrost to get the system to immediately turn on. The fact that the system works at all is pretty impressive. The airflow out of my side vents is okay but considerably less volume than the center. When you move it to a higher temp to activate the heat does the air output switch to the lower "heater vent" only?

aceuh
08-21-10, 09:22 AM
Congratulations on your purchase! The ac system on these cars are activated by a vacuum switch. Any leak in vacuum, I mean any, will effect the way the system operates. Jayoldschool is right about moving the lever to defrost to get the system to immediately turn on. The fact that the system works at all is pretty impressive. The airflow out of my side vents is okay but considerably less volume than the center. When you move it to a higher temp to activate the heat does the air output switch to the lower "heater vent" only?

Thanks! I'm really diggin this car so far. The people I got it from had told me that the A/C had been working but the clutch went bad on the compressor. I installed a new compressor and drier and juiced her up and it's blowing cold again....or at least out the center vent. I did turn it to a higher temp for heat and I could hear changes...You know the sounds of vacuum and doors moving. Air was still coming out of the vents about like it was when the A/C was on....didn't think to check the floor vents though.

Garys
08-21-10, 12:15 PM
I used this link and was able to get my entire climate control system to work like new again. It did not even power on when I bought the car.

http://www.stampie.com/tech/Climate1.html

I can almost guarantee that you have a small vacuum leak(s) in your system.

aceuh
08-21-10, 12:25 PM
Thanks! That looks like a great starting point for a diagnosis!