Re: zg wiring harness
The one on the left is a Circuit Breaker (like a resettable Fuse) and the item on the right is a relay socket.
If the ZG wiring is unmodified then that will be the power feed to the electric windows and rear glass demister. The LH wire on the LH unit should be Black with a White stripe. The relay socket will connect to the battery, chassis, the cct breaker and accessories power circuit.
If your XA does not have electric windows or rear screen demister then this wiring is not required.
The XR family ---->
Muzza: a XR8 AU seriesIII...bog standard :)
TBH: (the better half) drives an ED XR6 wagon (Mock Dev 4 160rwkw, JMM extractors, 4 electric windows, Ghia door panels in XR trim, rear head & arm rests in XR trim, Momo s/wheel with Cruise, EL thermos, EBGT wheels, etc) things to come soon = EECV upgrade.