3 brake lights out on 99 Accord EX
 

My 99 Accord has 3 of the 4 inner brake lights out and I'm needing some help diagnosing the cause.

The brake lights that aren't working are the 2 innermost 'white' lights and the Left red one that sits beside the white ones. The Right side outer/inner red one is working fine.

So far I've tried replacing all the bulbs and cleaning the contacts with high quality contact cleaner, and jiggling wires and connectors with no luck.

I checked continuity of all the grounds and they were excellent.

I also took a set of voltage readings (green wire to ground) and here's what it's showing:

*please note that when I say 'outer brake light' below I'm referring to the one that sits between the innermost white lights and the outermost(Big) brake/taillights

1) Right outer brake light (The only one that's working) = 11.5VDC

2) Right inner light = ~OVDC

3) Left inner light = ~ 0VDC

4) Left outer light = 11.5VDC! (yet the bulb won't light) ??

I even double checked this situation by swapping the bulb that was in the working Right outer with the Left outer and still got the same result - 3 lights not working

Any ideas on what the cause is? How to further troubleshoot?

Thanks

have you checked the ground wire?? socket ok??
UHMMMM,,, i thought that it only had brake lites on the outside ,( and 3rd brake lite) ,inners were only for tail lites ..
cannot recall 100% for sure

Yep, you're correct - I think I had which light was which confused.

The 3rd innermost 'white' lights should be the backup only lights If I'm understanding the manual correctly. So that makes sense that they don't light up when the brakes are pressed.

I also didn't realize that the 2nd red light( outermost on the trunk) uses a dual filament bulb and apparently serves double duty as part brake light and part parking light - is this correct?

The light in question will light up when the parking lights are turned on but will not light up when the brakes are pressed. So I guess it's just a bad bulb.