The relay is required on the fan switch to get the switch to light up when it is turned on with or without the headlights on. The fan switch originaly only has a ground running to it and provides a ground to the fan relay to turn on the fan. It needs to have a positive (Battery +) runnig to it for the LED or Light in the switch to function. This is why I used the Relay. The switch now has a positive wire and uses this to operate the relay and the relay complets the original circuit for the fan to work and the switch now lights up when it is in the on position. You will not need to do this for the fuel pump switch, only the fan switch. Feel free to send me an email if I can be any more assistance.
www.matthew@flpcars.com