Help no rear brake light only 3rd brake light

[Dylan Bobek]

I have a 1988 fifth Ave it lost rear brake lights suddenly I checked all the connections and everything checks out I have checked the brake light switch and it is working as far as I can tell I just have the 3rd brake light functioning at the moment the park light and blinkers work thank you

 

[Mikes5thAve]

Thus sounds the same as another post. Did you loose interior lights too?

 

[Dylan Bobek]

Thus sounds the same as another post. Did you loose interior lights too?

No just the brake lights

 

[Aspen500]

A good possibility is a wire broke off at the turn signal switch in the column. The 3rd brake light doesn't go through the signal switch, it's activated directly from the brake light switch. The other brake lights run through the column switch.

I say it's possible because I ran into the same symptoms many times at work "back in the day".

 

[AMC Diplomat]

Either bad ground or your bulbs burned out, those are my useless guesses

 

[Justwondering]

AMC --
Not useless, very worthwhile... I resorted to buying bulbs in a box instead of 1 or 2 at a time. No matter how well I think I have the water intrusion eliminated-- it finds a way.

JW

 

[Aspen500]

If the signals work, the bulbs and ground are OK.

Power from the brake light switch goes to the signal switch. When the signals are off, it connects the power to both brake light circuits. When the signals are used, the contact to that side brake light is cut, and the power from the flasher is connected. If the wire to the signal switch from the pedal switch breaks off, the signals will still work (as mentioned, the 3rd brake light doesn't go through the signal switch).
Everytime the signals are used, the brake light power wire flexes. It's very common to have it break right at the switch.