How to fix a 1996 s10 4.3 4x4.

Hello, none of those parts you've mentioned would have any influence at all and where the air comes out of. Not a single one of them. You either have a vacuum motor issue for the mode door, or a vacuum issue itself. The vacuum issue would be - detached hose, or broken hose -- or supply issue, not how much engine vacuum is produced. That's not a problem. The temperature of your air conditioning system has nothing to do with where the air comes out of. Even coming out of the defrost vents, if you have the setting to cold, you should get cold air if the air conditioning system is working properly. Sounds like maybe there still a problem with the air conditioning system itself as well. The potential causes of your concern here are many -- so I can't really guess or list them because it's pointless without hands on assessment. Another note, air conditioning refrigerant handling should be done by professionals only. Unless you have a certification as referenced in EPA section 609, you shouldn't be handling refrigerant at all. Venting refrigerant to our atmosphere is tremendously detrimental. Even if accidental. Therefore proper equipment and handling of refrigerant is essential. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops