Having fault finded the components in the coolant fan circuitry and found them all working or able to work as they should it leaves the wiring to be checked for continuity. Now the ecu has 112 pins and are arranged in 3 blocks, 2 of 32 pins and one of 48 pins. Each block are marked in a alphabetical horizontal sequence and vertical numerical sequence. The wiring diagram shows the wiring going to/from the ecu with a numerical number in the range of 1-112. So is there a tie up between the ecu pin identification method and the circuit diagram method so that I can identify what pin it is on the ecu from the diagrams method i.e say 84 on the diagram, which block and then which alpha/numeric grid position does it equate to?