Major brake light issue

[i_c_the_light]

Major as in I can't get them work! I'm working on my project build, which is an RS-RA body and using GT components to finish get it working. Okay, so the entire front harnesses are from the GT, and the rear harness is the original RS-RA. They are both of the same MY (only 5-6 build months apart). I'm totally confused since everything should be P&P and just work, but it doesn't. I've ruled out the switch at the brake pedal too. The rear lights do work when I turn on either the park or headlights, but when I stamp on the brake pedal I get nothing. Where does that leave me? I can't find any relay, and I've checked every fuse I can find and all are functional.
To make matters more confusing I'm using a service manual for the Aussie spec on a JDM sedan using JDM wagon parts.

Indicators are also a go (for a day), but I haven't sorted out the reverse lights since they aren't vital.

Also can the hazard/indicator control unit be fixed? Mine recently started to make a weird buzzing sound and I've got no indicators as well.

[log1call]

Sounds like bad earth to the rear lights to me. The brake light earths through one of the other circuits I'm guessing. No earth for the rear indicators could, possibly, cause that buzzing too.

[i_c_the_light]

The indicators were working, but then decided to fail. The buzzing is coming from the actual control unit for the indicators. That's easy, but I can't drive this car without the brake lights functioning.

Wiring diagrams aren't helping me find any earths for the brake light curcuit. All I know is that the brake and horn share the same fuse.

[magicmike]

jeeze you have to start somewhere.

1. Do you have 12 volts at the brake switch. YES or NO

[i_c_the_light]

im waiting for a multimeter to arrive, till then I'm in the dark.