I know it's too late to help but my friend built this device that basically "powers out" the PC's. It may be a help to others who are doing this job.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250