Thanks for that. It could be. Not sure how I would use it though.
I have not been able to test the D4 yet, bought it 2nd hand over a year ago and only serviced it yesterday. Thought I needed a slotted socket to remove the glowplug but when you are doing a full service and removing the fan unit a standard spanner will remove it.
Think I will just have to attach the wires from the Easystart 7 day timer and give it a go.