1 - 348 AC System Tech Article -
http://www.ferrariforum.net/tech/view.php?id=14
2 - the wiring harness socket pin connectors are the typical 348 window in-op issue.
3 - the seat belt assemblies crap out routinely, the TR's had a Factory Recall, notsure if 348's were included, but worth looking into, otherwise needs a new unit.
HTH's
Regards, JRV