Cadillac Repair: 91 Cadillac Eldorado Biarritz A/C, cadillac eldorado, vacuum line

Question
I noted a question you received dated 7/18/07 relating to a A/C problem on a '93 DeVille  4.9 engine where all A/C components had been replaced and cold air was going through the defroster.  I have the same situation on a '91.  You indicated you had pictures and diagnostic procedures available via e-mail.  Could you send me those?  I could also use a schematic.  I submitted a question 8/24 but no reply.  Thanks  Bill

Answer
Hi Bill,

      We are prohibited from sending pictures or diagrams and apparently the Caddy expert didn't get back to you for that reason.

      The reason that air is only coming out the defroster is that it has gone into default mode. In other words the a/c programmer probably lost its vacuum supply and when that happens air only comes out at the windshield so at least you can see to drive.

      To fix your problem I would look for a disconnected or open vacuum line and the most likely place would be the vacuum reservoir next to the brake booster. If your parking brake doesn't automatically release as well then the release solenoid or the switch above the steering column could be disconnected or have a hole in the diaphragm.

      Hope that helps. Bill