If the wire was fused between the relay and the preresistor, do you think the fuse would have been in the fuse box, or would it have been an in-line fuse somewhere else? I'll have to take a closer look and try to trace the wire from the preresistor back to the relay, but it disappears into a bundle that runs along the left fender toward the driver--very difficult to trace. Maybe there's a fuse somewhere along the line.

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles