Right, the first thing is the ground for the gauge is shorted to earth, that is what is causing that problem.

The trouble though, is where the wiring has burnt, it could have shorted wires together etc inside, you may even need to cut a section of the loom out and splice another section in, I had to do this with mine where some numpty had done a dangerous bodge.

As said there are two fusiable links, one or both of them have probably blown due to a short in the first place, so it's not just a case of replacing them.

Does your fuel pump prime when the ignition is switched on? It sounds as if the live power is there as you have run another feed as well, but most likely there is a problem on the ECU side.

The coil is not connected to the dash, the only thing they share in common is they both share a switched power feed. The only thing that is connected is the rev counter.

Martin