Cadillac Repair: A/C and Heat also Transmission, cadillac sedan deville, number combinations

Question
QUESTION: I have a Cadillac Sedan Deville with a Northstar motor and my A/C unit nor my heater isn't working but the defrost does. Basically, my A/C and my heater stop working a couple of months back it started with smoke coming from my hood I check under the hood and the smoke was coming from a black box towards the dash. Where it read "crack this to service the A/C".... Also, the defrost works but nothing else. Another thing my transmission light pops on along with Check engine light after I drive my car for a long period of time non stop. But I guess after the car cools down the check engine lights goes off and this happened almost everyday. So, could you help me with these questions? Please!
ANSWER: Need YEAR and MODEL of vehicle.

Also is your problem is that the blower fan is not blowing air to the AC and floor heater ducts ?.

---------- FOLLOW-UP ----------

QUESTION: Sorry! I have a 1996 Cadillac Sedan Deville. So, if it's the blower fan would I need to replace the blower fan or what. Also, my A/C unit used to give off this funny odder when I turn it on. What about the Transmission and Check engine coming on?

Answer
Put your system on DEFROST. Can you feel air out the defroster vents and hear the heater blower motor running ?.

Put your system on AC. Can you feel cold air from the AC vents and hear the blower motor running ?.

Put your system on HEAT. Can you feel warm air coming out of the floor vents and can you hear the blower motor running.

E-mail me a picture of this black box tyhat was smoking to me at: onlineautohelp@msn.com

As to the check engine light you have to get the codes from the computer.

1. Turn ignition ON. Engine OFF.

2. Simultaneously push and hold the OFF and WARMER(^) buttons on your climate control panel for 3 seconds and release them.

3. Codes will appear on the other screen in the form of LETTER/NUMBER combinations with either HISTORY or CURRENT displayed with each code.

4. After the display stops displaying. Turn OFF the ignition switch and let me know the LETTER/NUMBER codes and if they are HISTORY or CURRENT.

as for the codes