2G Brake lights

[Mham2k]

Fixed a short in my harness to solve my brake and interior light issue. Now my brake lights only work when my headlights are turned off.

Any idea what could cause that?

 

[Dericsh]

All I can think of at the moment if all the wiring is correct is to make sure you have the correct dual filament bulbs installed.

 

[CKOPOCT]

So the brake lights work normally - nice and bright, including the 3rd brake light. But when you turn on the headlights at the combo switch suddenly none of your brake lights work...

Only thing I can think of is that you still have a power/ground issue. Is the brightness of the brake lights the same between brakes and combo switch? (Yes would indicate a single filament bulb like @Dericsh posed, or that you have a problem with the socket.)

Does the 3rd brake light come on when the headlights are on (with and without you stepping on the brake pedal)?

What did you do/where did you fix the wiring issue you mentioned? Where in the harness? Any corrosion in the sockets?

 

[Mham2k]

My marker lights have never works and over time the wire shielding came off and arced to cause the initial issue. I fixed that.

Yes they shine very bright. I will check the bulbs to ensure there the correct ones if they don't work i will have to work backwards in short town.