Horn Help

JerMar

JerMar

Member
HELP....I have a 28 Sedan. I have tried everything to get the horn to work but every time I hook up the two wires the horn gets hot and then starts smoking because it gets hot. This is a new rebuilt horn. I have put a new horn rod in, new light wiring harness, tried 3 different cutouts and 2 different generators. I have double checked all the wiring diagrams and everything is hooked up correctly. It just seems like it is constantly getting juice to the horn...I am clueless now!!
 
Power comes from the cutout to the horn, through the horn up the steering assembly to the switch and when button is pressed, to ground completing the circuit and making the horn sound.

When you hook it up as you state does it blow?

If you remove the cars wiring and use a battery charger does it get hot or does it blow?
 
Do you have a Model A club in the area. Every club has their own horn specialist. Seek their help as obviously you are in over your head. Wayne
 
The horn should always have 6 volts going into one contact, then through one field coil and into the commutator, then out through the other field coil and into the other contact. When the horn button is pressed the ground side will be completed, so the ground contact on the horn should go from 6 volts to ground potential, or 0 volts.

Be sure both brush holders have insulating washers on the inside of the motor frame, and on the outside under the mounting screw heads. There should be no continuity from either horn contact to the ground or motor frame.

Many Model A's have a repro horn which has the motor grounded, so this will throw off all the normal Model A horn checks.
 
Please give more info on "a new rebuilt horn." An original or a repro? Who did the rebuild?

In the meantime, take two pigtails from the power, one positive and one negative, and touch each of the contacts in the horn. If it works, the problem is in your wiring. If it doesn't work, the problem is in the horn. Also make sure the armature adjustment is loose enough to allow it to turn.
 
The Model A ahooguh horn is normally not internally grounded. The motor "floats". The idea is that you can hook either horn wire to power and ground the other to make it ahooguh.

Whoever rebuilt the horn may have internally grounded one of the leads. Unhook both wires and with an ohm meter check each terminal of the horn to the body of the horn. There should be an infinite resistance reading. If there is a resistance reading look for where it is grounded.

Tom Endy
 
No it doesn't blow....if I hook it to the battery directly its the same thing, it gets hot. This is a rebuilt original that purchased from twlucas on eBay... Thanks for all the help!
 
Last edited:
JerMar said:
No it doesn't blow....if I hook it to the battery directly its the same thing, it gets hot. This is a rebuilt original that purchased from twlucas on eBay... Thanks for all the help!
Click to expand...

Did you back off the adjustment screw and try it?
 
Follow the following instructions with horn cover removed.
Find the wire that goes to the bottom of the steering column and up to your horn button and connect it to one of the horn wires using a push on connector. Find a negative (-) wire and connect it to the second horn wire using a push on connector. Nothing should happen if your horn motor as long as your motor is not shorted.
Now press the horn button, you should hear the horn motor running. The horn motor is a dc motor which can rotate in either direction depending on the polarity connections of the 2 motor wires.
 
CT Jack said:
Follow the following instructions with horn cover removed.
Find the wire that goes to the bottom of the steering column and up to your horn button and connect it to one of the horn wires using a push on connector. Find a negative (-) wire and connect it to the second horn wire using a push on connector. Nothing should happen if your horn motor as long as your motor is not shorted.
Now press the horn button, you should hear the horn motor running. The horn motor is a dc motor which can rotate in either direction depending on the polarity connections of the 2 motor wires.
Click to expand...



So instead of hooking it to the cutout hook it straight to the horn? How will it get power then?
 
The motor is a series wound motor, so it will spin the same direction no matter which way the two connections are made. Can you turn the armature with your fingers?
 
Does the wire from the horn go on the same terminal on the cut out as the wire coming from the terminal box?
 
If your cover screw is too long it can short out the brush holder giving you a really good short, I would assume that you didn't have the cover on when checking, when shorted the wires get hot quick.
 
I have contacted the person that rebuilt it and I am sending it back to him to fix and send back to me....thanks for the help....I will let you know what happens....
 
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