There isn't a single port on a phase 1. Each device has it's own port.
ABS - right next to the ABS unit in the engine bay
Airbag - under the rear seat
Engine - behind the carpeted side trim in the passenger footwell.
You can sort of see the engine port it in this photo -
See the white & red lead running across the top, parallel with a black wire and crossing over the green connector? That's it. The red circle on the extreme left is part of the 3 pin connector. ( Sorry not the best illustration but it does give you some idea!).
You'll need a 3pin adapter lead like this http://www.ebay.co.uk/itm/Fiat-3pin-...item3a66ab210c
to use with the lead you linked to. The red and black leads need to be connected to battery + and -ve for it to work.