1978 Mercury 90HP - Help on testing trigger&igntion coil

I have replaced all the wiring in my motor, also the stator(bad corroded wires) starter soleniod. I was told(on here) it was fairly easy to test if your ignition coil, trigger have gone out. While I am at it I want to check the switch box.... these ar about the only things I have left that have not needed to be replaced. I don't want to replace anything that I don't have to, but I just need to know the best way to test each. I did look on CDI, but I didn't see where or how to test. To give a little history on the motor.....picked up motor, runs perfect but I noticed the prior owner had rigged some additional wiring. After second time taking the motor out(runs perfect/strong) I got home and noticed all his wires were almost melted. So I have now replaced every wire on the motor, with new good wires. After doing all this work I noticed the wires going to the stator were just as crappy...so that was replaced also. Well now that all this was done I went to hit the motor to start her up and it started then stopped and wouldn't start again. So I am guessing it has to be one or all of the above. I want to test each and replace if needed. I have found ignition coils for around 99.00, and the well loved switch box for 500(stupid!!). I haven't found a trigger yet, but thought I would just test it also. Thanks for any help, I not all that smart with motors...but if in lamen terms I can handle it. Thanks