Motronic Failure

My newly rewired HES failed, due to the alternator belt shredding and wrapping around the lower pulley and taking out the HES sensors. I replaced the HES with a new one but still had no spark, nor fuel. Coils tested good so I went sniffing. I picked up that electronic burned odor from the motronic. Just to be sure, I disconnected the HES and ran jumper wires to the terminals and the HES and had no power from the Motronic. So, a used Motronic was ordered and installed and she fired right up and have had no electrical problems since. My question is this: Did the failure of both HES sensors cause the Motronic to burn out or was it coincidental that it burned out on its own due to age, mileage or whatever? I had read somewhere on the web the Motronics seldom fail but that's web talk.

My newly rewired HES failed, due to the alternator belt shredding and wrapping around the lower pulley and taking out the HES sensors. I replaced the HES with a new one but still had no spark, nor fuel. Coils tested good so I went sniffing. I picked up that electronic burned odor from the motronic. Just to be sure, I disconnected the HES and ran jumper wires to the terminals and the HES and had no power from the Motronic. So, a used Motronic was ordered and installed and she fired right up and have had no electrical problems since. My question is this: Did the failure of both HES sensors cause the Motronic to burn out or was it coincidental that it burned out on its own due to age, mileage or whatever? I had read somewhere on the web the Motronics seldom fail but that's web talk.

Afternoon Roger

No way to know for sure without doing a root cause failure analysis but the odds are that when the belt ripped up the HES wire harness that shorted current across the harness & sent that current back up a sensor wire then into the Motronic.

I would be interested if this could be related in any way to your 14.7V regulator diode modification as I'm getting ready to perform this myself. Swapping the previous owner's PC680 and staying with 14.4V for a FLA battery is tempting as is Odyssey drycell (apparently CHP choice although more research needed).

Bert, I'm not the Roger with the regulator diode mod. I think that is roger 04 RT