Well I couldn't find the multimeter so I've got to do some more digging around in the mess that is my garage.. I did try holding a bit of wire between the red and yelow/black & blue/black solder joints on the barrel and nothing happened
Like TT said earlier in this thread I must be missing an earth somewhere. So here's what I've got, does it anything jump out as missing?
1) battery - to battery tray (chassis)
2) big black wire from the starter bolted onto the gearbox
3) earthstrap going from the back of the head to the battery tray
4) fusebox common earths onto the tunnel
5) edis,megajolt,tps,coil,etc earth onto the on the tunnel
6) instrument cluster earthed onto the tunnel
7) steering column stalks earthed onto the tunnel
8) fuel pump earthed onto the tunnel