Cadillac Repair: caddy, coupe deville, climate control

Question
I've got a 1980 coupe deville cadillac, with a 6.0 engine, (RWD). How can I check the codes on this car? Thank you sir.

Answer
1. Turn ignition switch ON. Do not start engine.

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

3. NUMBERS will appear and then the display will stop at .7.0

4. Write down exactly how many times each number displays as if you were video taping the display and let me know what you see.

5. Turn ignition OFF.