07-14-2013, 08:19 PM
Anybody ever troubleshot their coupe's 3rd brake light? Mine stopped working about three years ago (so before I started my project), so I thought I'd take a look at it again, and here's what I've found:
- The regular brake lights located in the corner tail light assemblies both work
- The light strip itself (minus one non-functioning bulb) works when I remove it and apply 12V across the contacts
- All the fuses in the fuse box are good, but I haven't checked the ones in the drivers side footwell
- I've traced the wires back as far as I can (which isn't very far), and I'm not getting any voltage across these wires when I press the brake pedal.
Here's as far back as I could trace the wires:
These wires quickly disappear under the hatch insulation, and I can't see where they come out. The wiring for the rear window defroster are readily in sight, but not the wires for the 3rd brake light. Also (as usual...), I can't for the life of me find a trace of the 3rd brake lights assembly in the wiring diagram.
Any advice from anyone who has ever lost their 3rd brake light function? Thanks.
- The regular brake lights located in the corner tail light assemblies both work
- The light strip itself (minus one non-functioning bulb) works when I remove it and apply 12V across the contacts
- All the fuses in the fuse box are good, but I haven't checked the ones in the drivers side footwell
- I've traced the wires back as far as I can (which isn't very far), and I'm not getting any voltage across these wires when I press the brake pedal.
Here's as far back as I could trace the wires:
These wires quickly disappear under the hatch insulation, and I can't see where they come out. The wiring for the rear window defroster are readily in sight, but not the wires for the 3rd brake light. Also (as usual...), I can't for the life of me find a trace of the 3rd brake lights assembly in the wiring diagram.
Any advice from anyone who has ever lost their 3rd brake light function? Thanks.

