The wires are as follows.

The2 wires with Ring Terminals on are Battery + & -

The thin wire (red or sometimes white) needs to go to ignition feed so that your fans only come on with the ignition.

The other 2 wires that your on about do go to the fan switch, However as your using an Escort Cosworth Fan switch you have 2 options. The Escos Fan switch will turn on your fans at 2 different temps usually called fan low speed and fan low speed. The kit you have there will only turn your fans on at one speed.

Option 1; find which pins go to the high speed fans with a multi meter and wire your new loom to that.

OR

Option 2; Fit a Sapphire Cosworth Fan switch that is a 2 pin variant and will switch the fans on at one speed. This switch is a direct replacement for your switch

Hope this helps.