GMC Repair: Fan Air Direction, vacuum leak, buick lesabre

Question
Hello,
First of all thanks for taking the time to answer my question. I have a 1998 Buick LeSabre Limited. I've been having issues with the blower not working. The other day I replaced the blower motor and that fixed my problem. Now I am not getting any direction with the air flow. I can have it set for any direction but it always blows defrost/floor. Not that this is a major concern to me but I was wondering what may be causing this problem and how hard it would be to do the fix myself. Thanks for your help!

Answer
Hi
when there is a vaccuum leak, the HVAC system defaults to the defroster mode.
I would HIGHLY suspect a vacuum leak. Since you replaced blower motor, I would check on the engine on the firewall side for any "hissing" sound when engine is running.
Check all under hood for hissing sound (vacuum leak).
I hope this helps
Good Luck
Pawl