heater Problems

i am having heating problems with my 93 olds cutlass supreme. the heatercore and thurmastat have been replaced. all the different blower selections work but the air coming out is luke warm. i dont have a lot of $ to take to a shop and keep replacing parts that dont need to be replaced. input or input from experience would be greatly appreciated thank you!

I was reading up on the whole vent work in an oldsmobile service manual. and if i remember correctly there is something called a Programmer. which has one vacuume line from the engine that goes into it. and it routs all the other vacuum lines to the vents so you can switch vents. and i belive it has this arm on it. like a little plastic arm that moves according to temp like COLD or HOT. maybe the rod on there needs to be adjusted so it moves more and allows more heat. or maybe the entire programmer has a little problem. like the motor or something. if you dont want to mess with it then dont. but it might help. it could also be the climate control stuff. like the switch to adjust heat. but i dont think that would be the problem...any more questions let me know