If you have no CEL light then you should check to see if you have 12v on pins 3 and 9 at the ECU connector. This will tell you if the ECU is actually good or not, instead of just throwing stuff at it.
If you do have juice there, then the CEL is connected between pin 32 and ground. You could use that info with a test light to retrieve the codes.
So, first check that the ECU is getting juice in the first place. It might not be getting juice even tho you replaced the ign switch.
***--- Wrecking Crew member ---***
"I've prolly been around longer than you think"