Classic/Antique Car Repair: Blown Fuse on Starter, good luck jack, little notch

Question
QUESTION: I have a 1929 5 window coupe. I went to start the car and the fuse that is on top of the starter blew.  I replaced and it immediately blew as well when I turned the key.  Any idea where the short may be? any help would be appreciated.
Bill

ANSWER: If it blows when you turn the key on, that tells us it is not the lights or horn.  That makes it easier.  Be sure that is the case.
Assuming it is,  The circuit goes from the ignition switch , down to the dist that grounds that circuit when the points close.  That can't blow the fuse.  From the key on down, there is nothing that would draw enough current to blow the fuse.  Lets assume it blows before you turn the key on:  Disconnect the light harness from the gen or alt.  What it left is the horn.  It has to be the horn or a light, including the brake lite switch.  

If you don't find it that way, check this:  (new fuse),key off, you should have power on both sides of the coil.  There is the outside chance that your coil is shorted internally.  That would blow a fuse.  MaKE SURE THERE IS NOT A SHUNT ACROSS THE TWO COIL POSTS.  My guess it that it is in your light circuit.
Good luck.
jack

---------- FOLLOW-UP ----------

QUESTION: Jack, thank you for such a quick response!! I have had the horn apart and put it back together...and the car was fine.  I will disconnect the light harness like you suggest to see if fit is the horn first.  What am I looking for?  A frayed wire?  Wlould I have to take the light/horn button off as part of my investigation if the lights and horn are not the problem?  Would the movement of the light switch cause a wire to become frayed?  As you can tell I'm new to this.  Thank you for your help!  I tried putting a bigger fuse in and it blows immediately...without the key turned...Thank you, Bill

Answer
Take a look at the little wire that feeds the instrument pnl light.  They sometimes get pinched by the IP plate.  There is a little notch for the wire to go through.  If it is the lights, just take the headlamps apart and look for something touching ground.  Same with tail lights, and then there is that damn brake light switch.  You have to get under to check that one out.  It's not a big deal to pull the light switch.  Just pop off the bale and pull it forward.  I don't think it is in the column.
Good luck and stick with it.
jack