caod09

Please help, I did a search, but either my skills aren't too good to search or this is a 1st of its kind.

Bought a 93 SC300 last year (R-12). A/C was not cold, so I had it converted to R-134 and the mechanic filled it up.

A/C would have a random 10% chance of blowing cold, so I replaced the Magnetic Clutch Relay under the hood with junkyard relays. Also replaced the A/C unit with a junkyard one (I think from a 96, it has an orange screen) because my old LCD screen was bleeding/unreadable. I did the diagnostic test (holding auto on and recirculate) and got no codes, 00, so that is a good sign. I picked up a compressor from the junkyard, but accidently found out how to make it work.

So 2 things I found out:
1. A/C has a higher chance (I would say 70% of the time) of blowing cold air. It only works when I push Auto, but NOT when I hit the side arrow buttons (to turn on the fan) and A/C.

2. It blows at MAX, even if I tone it down with the arrow button, it doesn't blow slower/less. In order to do so, I have to turn off recirculate and put it in fresh air mode. It also doesn't beep when I hit any buttons. These 2 things I concluded was because I used a different/newer A/C unit.

My main concern is how do I fix this so that when I hit A/C, I will get cold air and not hope it will get colder? I'm thinking it has to do with the outside air temperature sensor or the auto a/c temp sensor? which one is which on top of the dash (left side/right side)?