No guarantees, but this is best I have found, a lot of links are dead because Tesoro went out of business 7-8 years ago
Tesoro/Laser 5 pin coil wiring
Pinout TX coil = (pins 1 and 3) orange and purple.
RX coil = (pins 4 and 5) grey and screen.
Pin 2 is not connected.
The purple wire is connected to the screen within the search head. so one wire is a shield blue/purple and is not used, only on the coil wire itself..