FARIA water/oil temp gauge wiring diagram

[Rustydory]

I'm trying to locate a wiring diagram for my Faria water/oil temp gauge. It stopped working and when looking, I found a purple wire disconnected. I'm afraid to even try to attach it to one of the 3 posts in case it shorts something out. If anyone has a gauge like this, I sure would appreciate a copy (email or fax) of the wiring diagram. I went to FARIA online and just can't make out the instructions because all my wiring is encased in a black plastic tubing and am just too unsure.

Thanks!