Need help with 3rd Brake Light

Question

Let me state up front that I know next to nothing about automotive electrical circuits.

With that out of the way, my third brake light quit working. I noticed that the wire leading into the housing was broken, so I spliced that back together.

I know a little bit about using a test light, and I can see that juice is getting to the bulb sockets. However, the bulbs aren't illuminating (and both "poles" of the two sockets I checked appear hot).

Here's a pic of what I'm working with:

How is this grounded? With only a single wire leading to and from the housing, I don't understand how electricity flows through this.

gary_ · Answer

It looks to me like the single wire that runs upwards from the three bulb sockets should be a POSITIVE wire, and the green wire that connects all three bulb sockets is expected to get its ground when you put the sockets back into the holes provided for them.  They are hoping that the bulb sockets will ground themselves to the chassis by having a metal bracket!  That is my opinion of it.  However I could be wrong.

anconn · Answer

Gary. wrote:It looks to me like the single wire that runs upwards from the three bulb sockets should be a POSITIVE wire, and the green wire that connects all three bulb sockets is expected to get its ground when you put the sockets back into the holes provided for them.  They are hoping that the bulb sockets will ground themselves to the chassis by having a metal bracket!  That is my opinion of it.  However I could be wrong.X2

steveb · Answer

I'm going to guess that the green wire is broken off and is hiding back behind the housing. Those sockets have no external ground.

bfast54 · Answer

Ditto on last reply...UNLESS metal coacts, dirrect to where the bulbs mount, which is also metal...A wire is missing.

You could add/ replace the missing gren whire, and ground where it is hid by fixture.!!

shot-n-az · Answer

Thanks for all of the wonderful replies! I poked around a little more, and sure enough, there is a white ground wire hidden up in the plastic sleeve that covers or protects these hot and ground wires in the engine compartment. It appears the connectors are beginning to fail because when I opened up the protective sleeve, a connector fell out.

I'm going to reconnect everything and hopefully, that will be the end of this little problem.

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Need help with 3rd Brake Light

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