1990 sedan deville e.c.m?

I guy's i was wondering if anyone might have some input;I have 90 sedan deville 4.5L motor.The car starts but the problem is when it's running it's a light show in my dashboard.All the so called dumby lights flash;the air conditioning comes on and off;the car idel's great till the light show starts.This is a continous cycle every few seconds.Also there is a clicking noise under the dash when the light show starts.I went under the dash when it was running and wrote the number down on the box that was clicking which i later found out was the E.C.M. It seem's like this should be the problem(anny imput)i can get a nother for 100$. Any way i can test this? I'm just hoping this is the problem.Again thanks Mike

Today i tried to start it;Battery is good but i get all the dash lights and no starter?