My 88 IROC LB9 TPI with Crane Hi6 CD ignition..I had a power spike, faulty A/C clutch, the engine died, no spark and I needed a tow. I checked fuses, EST module (replaced), Exchanged ECM. ECM error codes all 12's...no ignition pulse. The car had been running great for the past 18 months until I tried the A/C.
I resistive checked the new EST module again and it seemed OK, the Crane box showed a constant red led (no pulses). I summarized that the white trigger wire to the Crane unit required a ground pulse to trigger..tried this and still no led pulse from the Crane box.
I'm assuming that the Crane unit is faulty and my only recourse is to rewire back to stock...something I hope to avoid, are there any other tests or procedures that can be recommended , your experience would be most appreciated.

No replies but some are viewing...may prove informative.
Sometimes it helps just to type out the problem..I was trying to avoid changing back to the stock ignition, however once I looked at the simple changes I went ahead and isolated the Crane and put the stock coil in...yup it was the Crane and because it's encapsulated repair will be a mess if at all. On the good side the car runs fine and by all reports the stock HEI ignition is a winner anyway.
Simple is best!