Strange turn signal problem

[JoshH]

I recently bought a 74 C10 that had been sitting since the mid 90s.  I'm going over everything trying to get it ready for the road, and one of the things I'm fighting now is the turn signals.  The odd thing about it is all the lights work.  If you turn on the flashers, all four corners come on and flash like they're supposed to, and the right side only turn signal also works properly.  The odd thing is when you activate the left turn signal, only the rear light blinks.  Neither light on the front flashes.  I was working on trying to get the cluster out so I could replace some of the bulbs that are burnt out, one of them being the left turn indicator in the dash thinking maybe somehow it could be related.  As I was wiggling it around trying to get access to stuff, I bumped the lever down and the left indicator started flashing.  I got out to look, and the lights on the front are flashing.  I turn it to the right, and it was still working as usual.  I flipped it back left, and once again, nothing.  Anyway, I could use some help with a schematic or something to help me figure out  what is going on.  Thanks.

[zieg85]

I have had a bad turn signal switch before do exactly what you are describing.

[JoshH]

I was playing around with it last night after I made the post and found it was something with the switch.  I had to fiddle with it a little, and I could get the front left flashing.  I kept playing around with it, and it seemed to start working pretty consistently.  I think it is just dirty, corroded contacts.  Thanks for the response.