[bttpe]

1993 Lincoln Mark VIII 4.6 dohc installed in a 65 Mustang - wiring harness extended so pcm and edis mounted in trunk. I did this by getting sets of connectors that matched the 16 pin and 42 pin connectors and make extension harnesses.

All harnesses were double checked and pcm in/outs verfied.

A new relay provides good 12V power to both coil pack inputs. We thought that maybe we had voltage drop during cranking.

Problem: The edis8 module has a good VR signal input (checked on an oscilliscope (smooth sine wave) and with voltmeter (200 ohms, 1.5 VAC during cranking). PIP basically shows no signal on the oscilliscope. Coil driver outputs just drop to zero when the motor is cranked. That agrees with an LED test I did on both coil packs. Just as soon as I crank the engine the LED just drops out - no flash or pulse indication.

I have tried two EDIS8 modules and this setup did run before.

Any idea why I don't see PIP signal or the coil output switching. It acts like something tells all the coil drivers to drop out just as soon as cranking starts. thanks