Join Date: Nov 2003
Location: Phoenix, Arizona
Ferrari Life Posts: 366
Diagnosing in cyberspace often backfires, but if you insist....
Possibilities: loose connection at oil temp sender, ground wire from engine to frame not re-installed, main harness connector bad connection, oil temp sender wire squashed between two pieces somewhere.
Without seeing the car, it's really hard to tell. The folks who did the service should take a look.