Headlight bulbs

[Robotstar5]

On the wiring diagram i have, the light switch and dipped/ main switch seem to be all one giant switch so no wires to cut and reconnect.

I know the sort of multi-function switch you mean, so it's time for plan B . As you are going to connect a relay onto the main beam output to supply higher wattage lamps, connect a second (suitably fused) one in the same place and use it to re-supply power to the dip circuit when you select main beam.

Note for connections : do NOT use tap connectors/scotchlocks (invention of the devil ), either strip insulation and solder or cut cable and crimp on connectors, preferably with a ratchet type crimper.

 

[gavuk]

Note for connections : do NOT use tap connectors/scotchlocks (invention of the devil ), either strip insulation and solder or cut cable and crimp on connectors, preferably with a ratchet type crimper.

Whilst solder is great ,with a little thought ,and using crimp connectors the relay could be bypassed in event of failure and the loom reconnected,assuming BS is correct about the loom being ok for 100w bulbs ,