Classic/Antique Car Repair: turn signals, napa store, system voltage

Question
I have a 1965 t-bird.  The turn signals on the fenders work ok as long as I am driving. As soon as I put on the brakes or back off on the gas pedal they quit working.  The turn signals in the front and rear work ok-no matter what.
Any suggestions?
Thanks for your help.  

Answer
This is one of the symptoms of a failing or incorrect turn signal flasher.  Remove the flasher from it's socket and take it to your local NAPA store - ask them to look up in their book to make sure you've got the correct one, and if so, just buy a new one.  If you've got the wrong one, then replace it with a correct one.

What is happening is that when you take your foot off the gas to step on the brake, or when you back off on the gas for any reason, the system voltage drops from about 14.5 volts down to about 12.8 volts. That should be enough to operate the flasher, but in your case, it isn't. Another cause of this is wrong bulbs in the brake or turn signal sockets, but that is pretty unlikely.  Your car came with 1034 bulbs in those sockets, and they may have been replaced with higher wattage ones, but I doubt it.  Try the flasher first, anyway - it's much easier to change, and cheap to buy.

Dick