feel air coming out of defrost vents only

08-07-2004, 11:37 PM
I took the 94 Buick Lesabre to get the ECM changed and my car now only blows in defrost mode. Think it had to do with the work the mechanic did or if not what is the problem

08-08-2004, 10:29 AM
Sounds like no vacuum to activate the air vents. There is a vacuum hose that goes from the engine to a vacuum accumulator box located on the engine firewall to the left of the master cylinder. Your heater/ac has a plastic line that also connects here. The default setting in the ac/heater unit is to blow air out the defrost vents.

If the problem is not found here, then the mechanic probably disturbed the vacuum line at the heater controls when changing the EMC (which is located next to the ac/heater controls).

08-09-2004, 10:08 PM
sure enough he knocked off a vaccum hose going into the firewall thanks for the reply. Its nice to see i gotta support group on the web

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