Battery loom to fuse box query

[nick28]

Morning, does anybody know if the small 4-5mm positive cable that runs together with the main battery loom from the boot feed the fuse box ? The battery was in the engine bay and they all joined together on the positive terminal block of the battery, with the new bracket that supports the new power cable on the bulkhead there is a separate location for this smaller power cable, as if a 'clean live' is used to feed the fuse box ?? Hope this makes sense .

Cheers
Nick.

[Brianmoooore]

The 'clean live' is for the feed to the engine loom. Fusebox feed goes onto the terminal that connects to the larger wire from the boot, along with the wire to the starter motor and ABS pump, if fitted.

[nick28]

Thanks for that Brian. You wouldn't happen to know why separate feeds are used would you ?

[Brianmoooore]

Separate feeds are used to isolate the engine electrics from voltage drop and noise on the supply to the starter motor and the rest of the car electrics. There will be a considerable voltage difference between the two terminals in the phantom terminal block when the starter motor is operating.

[nick28]

Ah i see, that makes sense. Thanks for explaining.