It's actually reasonably simple......
You need the following items:
<If you are only doing the speedo>
- TD5 speedo
- 2 x TD5 speedo connectors
- genuine transducer (all after market ones are rubbish)
- transducer connector
<If you are doing speedo and fuel gauge> {this is what I have done as I have re-used the original temp gauge}
- TD5 speedo
- 2 x TD5 speedo connectors
- Fuel gauge
- genuine transducer (all after market ones are rubbish)
- transducer connector
The connectors above are from PaulMC on here!
The wiring is quite straight forward and you CAN simply chop off the original connectors and attach the wires to the new TD5 connectors if you like. My choice would be to use a male and female multi connector such as a pair of ATX power connectors OR 2 PAIRS of male and female 15 way auto power connectors (if you do this then have one male and one female for each side which stops you plugging them in wrong! - making sure that the male connector that stays in the car only has ground or sender connections to avoid shorts.)
You need to remove the speedo drive cable and fit the transducer into the same hole in the transfer box then take 3 wires from the back of the dash to the transducer say yellow, white and black. connecting black to ground, white to ignition live and yellow goes into 1 connector of the multi block and will be the output from the transducer.
The wiring to go to the TD5 gauges is basically one to one.....
Ignition live from the car's loom to same on the TD5 gauge loom
same with ground, permanent live, side lights, left indicator, right indicator, fog light etc etc.......
However you feed your fuel gauge sender to the speedo and then take an output from the speedo to the gauge. The gauge has an intelligent system inside which keeps the gauge from going up and down as you go round corners and up and down hills.
Also a few wires need taking to ignition live or to ground or to each other to avoid warning lights coming on for things that you don't have such as anti lock brakes.
You can buy a wiring harness for the complete TD5 dash and make a few small mods which is probably easier than building it yourself if you are using the whole dash.
If you cannot find all the pin outs etc I can dig out my workings out and show all the connections.