My 83 Hatch has been throwing a code 12 since me and the moose converted it to an EA-82 carb and intake (BTW that was fun....) I thought it was just computer freskout garbage, but the other day i blew 5! ignition fuses. We found a harness that could have been shorting out and that fixed it, but i cant figure out what on an ignition system could be failing enough for a light, but not effect the car's starting or running. Any ideas?

does it show the code with the engine running or off?

my appologies, i forgot to explain the code. The ECS light doesnt show until after about 20 minutes of driving and stays on until you cut the car off......off course since it first started the blinky light always blinks

Well, code 12 refers to a starter switch or circuit problem. I'm really not sure what the computer is looking for with respect to the starter circuit.

 

I would suggest a dodgy ignition switch or connection. Perhaps you should try clearing the codes and seeing if it pops up again.