Cadillac Repair: heat cooling fan, code combinations, cadilac

Question
1993 cadilac eldorado touring 4.6
I am having a problem with the a/c heating system.
I have changed the blower motor and module but the same problem persists. turn on fan motor will run for 2min then shut off. panel is lit with temp and control but blower motor will not run on any speed defrost or vents.
can you suggest other areas to consider broken or split wire or relays?  all fuses are intacted.

Thanks Scott  

Answer
Go into diagnostics and see if you have any fault codes in your computers and let me know what codes you get.

1. Ignition ON.

2. Simultaneously push and hold the OFF and WARMER buttons until all the SEGMENTS display and release.

3. write down all the LETTER/NUMBER code combinations that appear EXACTLY in the oreder they appear until it stops displyaing and you see PCM?.

4. Shut ignition Off