Topic: Under dash yellow 3 port plug

[69GT350H]

Looked around but maybe I missed it, trying to figure out what the 3 wires are. I know the Green/Orange (left most wire) is for the Tilt-Away, and the Dark green (middle wire) is for the seatbelt reminder (I think that's correct). I'm not sure what the 3rd wire is, color or what function. Finally finishing up my dash wiring and this is one of the last puzzles.

Thanks

[69GT350H]

Parking Brake warning lamp?

Interesting that this is a special bulb with a thermal strip in it. When the lamp turns on, it heats the strip causing it to bend, opening the circuit and turning the lamp off. Once it cools the strip bends back closing the circuit so the lamp turns on. This happens quickly causing the bulb to flash or strobe.