93 maxima. Need AC help

I just purchased a car and believe the control panel is out. I simply do not have and will not have the money to fix it. There is some kind of "fix" that was told to the previous owner and he was going to show the owner but he retired and never did come show him. He did fix it for him though.

Problem: Switch wont go all the way left (cold) or all the way right (hot). It heats just fine and cools down a bit when switched to the left. (you can use a screwdriver to push on the spring to let the swith go all the way to the left) It does not get cold though, its warm at best.

The guy did not show my neighbor how to do it but he did it for him before he retired. He switched some kind of switch or something manually that would allow it to blow either hot or cold air.

Can anyone help me understand how this is done?

Thank you

It looks like I have a similar problem. I'm not sure if your problem is mechanical or electrical but mine seems mechanical.

One day I was switching the AC lever and I felt something break. Now all I get is level's 1 and 3 on my 93 Maxima. I plan to open the panel and see what's wrong.