I'm trying to trace the purple wire from the brake switch to the transmission plug on my 1988 GTA and want to verify a couple of things before tearing down the dash.

The diagram shows this wire going from the brake switch to the C207 connector under the dash and then on to the transmission connector. Is this correct and it doesn't go to the ECM? The diagram shows the other 2 wires in the transmission connector as coming from the ECM.

The two from the ECM check with a volt meter but the purple from the brake switch does not. I'm going to check the alignment on the brake switch first but if that checks out, I'll need to trace and check the wire.

 

Purple wire goes directly to the TCC soleniod on the trans to give 12V when brake pedal is at rest.

When conditions are right, the ECM will apply ground to the tan/black wire to close the circuit and lock the converter.

 

So it doesn't go through the C207 connector under the dash? It just goes across under the dash to be included in the bundle. From what I remember on dealing with the harness during engine swaps, the bundle that goes to the transmission comes out of the main harness on the passenger side and then down to the connector.

If this is a direct run, then, in theory, I could replace the wire with a new one from the switch through the firewall at a place of my choosing and splice it into the connector. Assuming the cause of the issue is old age breaking the wire somewhere and not just the switch being out of alignment.