Just driver side brake light not working

[Havic2u]

So I have a strange issue and just trying to get some ideals on where to start to t/s.
So I have a 89 GT conv that I installed LED taillights in. Everything is direct fit no splicing wires or anything
I noticed that the brake light just on the drivers side is not working.
I put the normal bulb back into the socket and it fails. I guess I didn't know it wasn't working.
So I am wondering can it still be the brake switch if it is just the 1 side not working?
The tails lights and turn single work just fine and the grounds looks to be in good shape.

I didn't see a post for just one side of the brake lights being out

Thanks

 

[General karthief]

Take a test light and probe the connections in the socket.