2002 Saturn L300 Electrical problems

For the gas gauge does it go to empty etc?How did you try to program the key fob it requires using a tech2 dealer scan tool?Also as far as the wrench light coming and and the car shifts hard then you turn the key off and on again it shifts normal. You should have a code P1811 for the hard shifting. My guess is your code reader cant read history codes. Usually the wrench light coming on and then shifting hard is a bad pressure control solenoid in the transmission valve body.I have replaced tons of them for that. Does your power door locks work with the door lock switch?With the gas gauge going crazy with the key fobs inop is usually a bad body control module I have replaced tons of them for that. When the gas gauge goes crazy does it ever not start?

So you changed the output speed sensor by the axle?Makes no sense to me why you lost power to the climate control and blower from changing that. Also did you check the fuses?