View Full Version : Air Vent Problem in 1988 Brougham

08-21-07, 03:02 PM
I have a 1988 Brougham. I have only had it for a little while, and when I got into some rain yesterday and turned on my defrost I noticed that air would only blow down by my feet. I turned the heat on economy, and low and high and found that air still only blows at my feet.

I have tried to read all the old posts to find this problem, but I can only find it in newer Cadillacs. I have tried to find the vacuum lines, but really do not know what I am looking for.

I also have read a bit about the digital climate control module, but I am not sure how to test it.

Anyone tell me where to start here? How can I determine if I have a vacuum problem or a digital climate control module problem?

Thanks for any help it is appreciated.

08-21-07, 06:04 PM
Can only relate a similar issue - 88 Brougham - No defrost, only heat - Digital control worked with the warm-up delay - Temp control worked - Fan speeds worked - My go-to-guy found a vacuum line by the fire wall, in the engine compartment, by the wiper motor that was not connected, and didn't have an obvious connection point to fit onto - He cut an existing line and tee'd into it and the defrost came alive - The dash comes apart easily and you can get a vacuum gauge under the dash - The previous owner(s) have hacked at the old girl quite a bit and must have changed the blower assembly and didn't quite get-r-done: good luck

08-21-07, 06:21 PM
Vacuum hose under dash or vent control unit.

08-21-07, 09:16 PM
Okay, where is the best/easiest place to find the vacuum line?

How do I test the vent control unit?

Thanks again...

08-22-07, 12:02 PM
Thanks for all the help, I found a vacuum line unplugged. The air works well now, and the car even idles smoother.


Cadillac Giovanni
08-25-07, 12:42 PM
Just for my own personal gain, where was the unplugged vacuum line?

08-28-07, 03:03 PM
Cadillac Giovanni:

Tried to PM y ou back but the admin won't let me until I get 20 posts, so I will try to answer your question here...

There was a hard plastic tube coming from the firewall below the wiper motor, there is a soft flexible rubber hose that I had to plug onto the hard plastic piece.

Hope this helps, if not let me know and I will try to describe a bit better for you.

Cadillac Giovanni
08-28-07, 06:58 PM
Thank you, that was all i needed. The way I had been looking at it, that hose was just perfectly obscured from my line of sight

Thanks again!

12-14-07, 01:27 PM
Well everything seemed fine until it got cold out, now my air is blowing the way it was before. It only blows out at my feet, no matter what setting I pit it on.

Someone told me that there is a problem with the digital climate control module. Anyone have any info on this? I have tried to search but found not much pertaining to this problem.