[trebor]

There are only two variants of the FBH fitted to the 75, most are later model 98570B, early cars had a model 66232C, you need to be certain which model you have when testing. The model number should be on the Webasto sticker on the side of the

Remote starting For 98570B - its earth to Pin 3

Remote starting for 66232c - its +12v to Pin 1

As Trikey says it doesn’t matter which one you have as long as you know which one it is and wire the remote accordingly

You will need a working FBH, dosing pump and exhaust for a basic installation, the wiring will be present in the car , if you want to start it remotely then that can be done once you have it installed and working