Turn signals won't work

[Midlife Crisis]

My turn signals on my 1976 Honda CB 750 K4 have quit working.  They used to work but now when I flip the switch, the "horn" sounds, but the lights won't flash.  Instead, the (left or right) light will STOP working completely until I flip the switch back to normal.  I have replaced the bulbs (bought at an Auto Parts Store), replaced the Flasher/Relay (bought from a Honda Dealer) and still the same thing happens.  My bike has been sitting for the last 2 months in the garage with an occasional start up but I haven't had the battery on a trickle charge.  Could my problem be solved just by charging the battery overnight?  Is there something else I should be doing?  I rode it a few miles yesterday thinking that would recharge my battery and solve the problem but it didn't.  I thank anyone in advance for your help.        

[Re-run]

So your turn buzzer works but no lights at all? Usually 2 things, the switch or the wiring. It is not likely the bulbs as unless you replaced all 4, at least 1 should work. The flasher would not usually prevent them for at least turning on.
So I would check out your wiring diagram and make sure the wires are connected right. After that, I would carefully give the switch a good cleaning.

[Midlife Crisis]

Thank you Rerun for your help.  I forgot to mention that with the new bulbs, I still don't have working amber lights in the rear.  A friend of mine told me that it sounds like a ground wire problem.  But he also told me that "green" doesn't necessarily mean "ground" when it comes to motorcycles.  So I'm going to trace the wires and make sure all the connections are secure.  

[DesignBuild]

Your friend is right, green rarely means ground on motorcycles (usually just frame grounds, i.e. direct grounding). However, it could be a grounding issue for sure. From the symptoms it seems likely they aren't wired right, but if one is faulty with the stock relay the others might just turn on but not necessarily blink because the power draw is uneven, or other strange happenings.  

Personally i would go buy an electronic flasher from Autozone or somewhere similar for about 8 bucks. (i actually do use one of these) Pop that bad boy on and see if the others flash, the ones that do will be fine, the odd ball(s) out will have the grounding or possible wrong wiring issue.

goodluck  

[Re-run]

You will not have amber running lights in the back, only the front. The back only flash. Black is usually the "hot" or + wire.