Hopefully the diode didn't get zapped. Best to check it with a meter before installing.

 

I've got a few spare lol

 

The diode is the wrong way round and you have missed the link between 86 and 87 on the relay.

Les.

I honestly cant see what I've miss apart from having the diode the wrong way around

 

This part of post #34 "blue wire to relay 87, relay 86, top end of solenoid and D1 cathode. " ALL of these points should be connected together. You have the blue wire (From the car.) connected to 87a on the relay but you don't have the link between 87a and 86. The other two points of that node are connected together correctly. (86 to top end of solenoid and D1 top end. It may be a matter of interpretation of that part of the description. This is why diagrams (Schematics) are used as there is no ambiguity. Alec's diagram in post #18 is perfectly clear on the connections. The good point is that with that missing link in the wiring it is unlikely the diode will have been destroyed by being connected the wrong way round as there was no power source connected to it.

Les.