Brake Light problems.

[Tonup76]

So my 73's brake light isn't working.  The light is on but the brake light won't come on when either of the brakes are pressed.  Here's what I've done and the result:

I've checked the bulb, NO
I've dissassembled the rear switch, cleaned and hooked back up, NO
Checked the wiring, I actually changed the tail light,but it wasn;t working even b4 I did that, NO

The thing that's weird is after I disassembled the rear switch and hooked it back up, when I press the brake it kinda gets dim.  Like there's something happening but not what's supposed to happen.  

ANY help of suggentions would be great, it's not a good feeling riding around with a brake light that dosent work.  

Thanks.

[Tonup76]

What a nightmare.  So I started messin with the wiring on my bike.  MISTAKE!  

Here's an update, I'd love some advice on this.  
After getting extremly frustrated I got the wiring back together and every thing seems to be working properly EXCEPT for my brake light, which was the original problem.  Iv'e got it narrowed down to a BROWN wire that comes from the tail light.  When I disconnect it the brake light goes out but tail light stays on.  Which means that the brake light is ON all of the time.  What the heck is wrong here?  If I disconnect the front switch, nothing happens, if I disconnect the rear switch, nothing happens.  It's something with this brown wire.  What is that brown wire??? a ground?  Could it not be grounded properly in the tail light?  The Wireing diagram says it goes to a fuse but I can't find it for th life of me, I followed it to the front of the bike and that's when I found the birdsnest from hell in the headlamp cover......any suggestions would be REALLY helpful.  If this dosen't make sense or you need more info please let me know.  Thanks guys.  

[Rod_Knockin]

i say its a ground issue. Does the reguar running tail light work? Just the brake light failed or is it both. there should be 2 or 3 wires to the bulb socket 1 running light 1 brake light and maybe a third for the ground. If there isint a third then it uses the light frame as a ground. If thats the case run an external jumper wire from the - of the battery to the frame of the light and test again.

[robotrick]

thanks for the post.... I'm having the same problem.  The filaments are fine and have been since I replaced the brake bulb. i replaced the harness and rewired the whole bike over the winter and it ran perfectly all summer.  the wiring hasn't changed since it worked.

one thing that did happen to my 74 750 is that the left front blinker light fell out of the housing, and was bouncing around inside the blinker casing.  i put it back in and the blinker worked fine but right after that, i noticed that the brake stopped lighting when applying either the hand and foot levers after that (running light has not been a problem).  the fuses are fine, the bulb is in good condition, i triple checked all the connections in the headlight, under the seat, into the fuses.... it's a mystery.

i tried your suggestion re: grounds but it still won't light when the levers are pulled.

i'm out of ideas. next, i'll buy a new bulb, but i'm 99% sure it's not that...

any more ideas?