ECM Problems?

[1986coupe]

I am not sure how to tell if I am having ECM problems or a bad ground.
I often here strange sounds in the radio before the service engine light or coolant light comes on. The numbers on the air conditoning do not always come on ( I already fixed the air conditioning so that isn't the problem)
I was reading my Haynes manual last night. I noticed the testing for the EGR solenoid because it could also be a bad wire or ECM. I used the tester and the light didn't work from one of the wires. As I was testing it the air conditioning fan came on. Is this a bad ECM?
Any help is most appreciated.

 

[jmccloud]

Troubleshooting good/bad news

After being really burned by some aftermarket manuals, I trust only the GM or Helms versions. That's the good news.
Your symptoms sound like someone's been monkeying with the wires or more likely a ground is floating (bad connection).
Only an accurate and complete wiring diagram and schematic can help in either situation.
I got a set of GM manuals from e-bay for 60 bucks - worth every penny - but they're very year specific so can't guess where you should look.
Good luck

 

[oldvet]

After being really burned by some aftermarket manuals, I trust only the GM or Helms versions. That's the good news.
Your symptoms sound like someone's been monkeying with the wires or more likely a ground is floating (bad connection).
Only an accurate and complete wiring diagram and schematic can help in either situation.
I got a set of GM manuals from e-bay for 60 bucks - worth every penny - but they're very year specific so can't guess where you should look.
Good luck

I,ve never noticed anyone mention your local library for references. My local carry all the chilton manuals and other odd ball books. When I cain,t find it in my haynes book, I make a dash for that place.