On my 86 the wires that clip on to the gearbox switch are part of the
engine loom. They run forward and upwards under the floor of the car, and
then up the firewall into the loom. They enter the loom at about the same
place as the #4 cylinder injector connection.
Both wires exit the loom via the large multi-pin plug that connects the
engine loom to the on-car loom. This connector sits on the firewall pretty
much behind and above the cam covers.
Inside the car the backup light circuit is powered from Pin #C15 on
Junction Block #3 wherever that is ??? Red-Blu wire from JB to switch
and Red-Blk wire from switch to lights. Backup lights wired in parallel
with a common earth to the chassis.
Hope this helps
Cheers.... jondee86
1984 AE86 Corolla GT Liftback, NZ new... now with GZE
spec small port, twinscrew s/c and water/methanol injection

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