[Mk2] [Generic] Wiring in a rev5 to rev3 conversion speedo?

[chaos19810]

I've nearly finished my rev5 to rev3 tubby conversion, today I rewired the fans, oil level sensor, both front and rear fogs and they all work on the standard switches but every time I put my breaks come on the rear fog indicator light on the dash comes on as well but I'm stumped by rewiring the speedo. I know its only one wire and stu has been kind enough to let me look at his and send me pictures but I still can't work out which to rewire?

Once I get this sorted I'll be writing a guide for others as this info is hard to come by

[toxo]

Turbos didn't have rear foglights so you are connecting live to the foglight circuit every time your brakelights come on. Should be easy to fix, you need a separate wire and some diodes for the fog light circuit.

Can't remember the speedo wire off the top of my head but I think they moved the position of the wire in the connector in the passenger footwell so you just need to repin there. From memory it's a purple wire in imports so look in there for a wire that doesn't have a partner in the other side of the connector.

The more I think about it the more I remember. There is a purple wire and a purple wire with a white stripe on import wiring looms. One is the signal from the speed sensor in the gearbox to the speedo cluster and the other is the VSS signal back from the speedo cluster to the ECU. They both exist in the same connector on the back of the instrument cluster but probably won't be purple in an UK car (if that is what you have) so some rudimental continuity checking with a multimeter should sort it out.