So, one day I was getting ready for the morning commute when my 1985 245 DL died suddenly at the edge of the parking lot. I pushed it back into a spot and it hasn't moved since. That was a few months ago. There's no spark from the coil--due to the fact, I believe, that there is no pulse coming from the ICU.

I checked the voltages at the coil. B+ on both low-tension leads while the key is in the ON position.

I checked the voltages at the hall sensor: 12V 5V 0V.

I simulated the function of the hall sensor by briefly jumpering the 5V and 0V leads.

I checked for power and ground at the ICU connector.

I cleaned and ensured a proper fit for the ICU connector.

I replaced the ICU.

In all cases, there was no pulse at the coil and no spark.

Is there some component in this circuit that I'm missing? I've heard talk of a 'breaker unit' (whatever that is) feeding a pin on the ICU but I have no idea what it does or where it is on the car. I really don't know what else to try.