1999 Oldsmobile Aurora Heater only work on passenger side.

OK sounds like the dual system, without having the benefit of the scanner and resulting codes, I think the temp blend door on your side is stuck, or the ambient temp sensor on your side is no good.
Look under the das at the heater plenum, see if the servo opens and closes the blend door. If there is no movement, disconnect the servo, see if you can move the lever by hand, it should move easily! If you need to get a can of white lithium spray, and see if you can lube it, then work it till it frees up.