[sambo]

Rob, my battery is in the boot and I ran a large, high strand positive cable to just behind my firewall where I have a massive fuse between that and the starter motor. This allows high current draw for the starter but prevents a major short back to the battery from any other component in the car.

Next I ran power from that main fuse to a number of terminals behind my dash for solenoid, accessories and ignition power. These are all protected by self resetting 20A circuit breakers and are fitted with relays. These circuits feed into a traditional fuse box to allow smaller fuses to be applied to individual components such as wipers, stereo, etc.

I have separate relays for low/hi beam for best performance - just as you're thinking. My lights use a modified Falcon loom for this section, which includes a horn relay.

My earths run from battery to chassis, plus braided cable from gearbox to chassis and also one from the engine.

The biggest learning curve for me was all the negative switching circuits in factory columns etc. I have a gremlin somewhere in my low beam circuit too - the H4 globes are dim on low but hi beam is fine. On my "to do" list as they say!