Horn doesn't work w headlights on

J

jkeller@nerej.com

Junior Member
When I turn on my headlights on my model A, the ammeter shows a zero charge. Also my horn will not make any noise. Can I remedy this by increasing the cha
rge in the generator by moving the adjustable arm? What did Henry do about this?
 
Increasing the amp output may help some but is hard on the battery and generator if too much. Fix the horn and its connections and you will have it back like it was new. Start with some 3in1 oil on the felts inside the horn cover that may be a good start.
 
So horn works with lights off? Or horn doesn't work?
Ammeter has nothing to do with horn or lights, just battery charge. If it shows no discharge with lights/horn and with engine off, then you have a disconnect between generator and lighting switch at the bottom of the steering column. Open it up and have a look, but disconnect battery first.
 
If the battery is good and being charged, no loose connections in charge path, then there is a wire not carrying current to the horn or a poor ground on the horn!
Did this just happen, or are there more facts to be told. Did this just start? Have U been doing any other things to the car you can trace back to relating. Be interested in knowing what you uncover.
 
I recently installed a new wiring harness with new metal contacts that "plug" into their respective sides in front of the horn armature. It works okay without the lights but it has always been poor when they were on. So this is an old problem for me. The battery is fairly new and the car starts right up. I am just getting everything back together seven years after dismantelling it down to the bare chassis.
 
I am perhaps guessing but a problem that has existed for years in some new wiring harnesses is that the manufacturer bundles the wires tightly together with an outside loom covering, and carries the tight covering too close to the plate the wires attach to and goes inside the switch at the base of the steering column. When this happens and the switch is attached to the steering column the spring loaded horn ground wire at the end of the horn and light rod will slip to one side as the contact it should be making cannot move because of its tight wrap. You have lost the ground contact. The solution is to carefully slit the loom covering back just a bit to allow flex. Sometimes this problem lets the horn work now and then or not at all, but if you have this problem the fix is not difficult.
 
you can move the third brush in the generator and put out more charge. but you will need to drive with your lights on during the day to keep from over charging your battery. the horn on my Victoria works better with the lights off and the engine running
 
First off, I agree clean and lube the horn. He does not say "WHAT" he has the output set at with the light off and motor running at a fast idle, so it's guess work on our part. Nor do we know "WHAT" head lamps bulbs he is running.
 
jkeller@nerej.com said:
I recently installed a new wiring harness with new metal contacts that "plug" into their respective sides in front of the horn armature. It works okay without the lights but it has always been poor when they were on. So this is an old problem for me. The battery is fairly new and the car starts right up. I am just getting everything back together seven years after dismantelling it down to the bare chassis.
Click to expand...

Let's try something, I assume you have a 6 volt system and an original Ahooga horn, kind of, is this true? It is not a 12 volt aftermarket horn? Next is, Prepare a jumper wire with a 15 amp fuse to assure if it gets shorted to ground nothing bad happens, get the back of the horn opened up to the wire that provides power to the horn. Turn on your headlights, and then take the jumper wire from power, at the starter and jumper it to the horn wire! If the horn blows, the loom wire carrying current to the horn is defective! If the horn does not blow, you may need to adjust, lubricate and check the brushes in the horn motor. Also is the armature commutator clean? Some things for U to ponder. Let us know what you uncover.
 
jkeller@nerej.com said:
I recently installed a new wiring harness with new metal contacts that "plug" into their respective sides in front of the horn armature. It works okay without the lights but it has always been poor when they were on. So this is an old problem for me. The battery is fairly new and the car starts right up. I am just getting everything back together seven years after dismantelling it down to the bare chassis.
Click to expand...

Let's try something, I assume you have a 6 volt system and an original Ahooga horn, kind of, is this true? It is not a 12 volt aftermarket horn? Next is, Prepare a jumper wire with a 15 amp fuse to assure if it gets shorted to ground nothing bad happens, get the back of the horn opened up to the wire that provides power to the horn. Turn on your headlights, and then take the jumper wire from power, at the starter and jumper it to the horn wire! If the horn blows, that is good, next do the horn button again with the lights on, if it does not blow, the loom wire carrying current to the horn is defective or the actual horn button contact is dirty! If the horn does not blow, you may need to adjust, lubricate and check the brushes in the horn motor. Also is the armature commutator clean? Some things for U to ponder. Let us know what you uncover. I am betting on the wire loom or horn motor maintenance, plus you state the headlights are not real bright either. Do you have access to a voltmeter, and can use one? If so you should be getting 6 volts at the horn and at the headlights, when they are on. If not, your wire loom is suspect. Sorry to ramble.
 
you also can put a relay in the horn cover to get full battery voltage,but I still would try and diagnose the problem.
 
Horn is connected directly to generator (and battery). Horn button provides ground contact. Dirt gets behind the horn button and is often the cause of the horn not sounding.
As for headlights, disconnect battery and check for continuity between the generator and light sockets, starting at the lighting switch.
 
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