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horn problem

 
hammoo46
New User
Posts: 7
Joined: 11/12
Posted: 03/12/13 11:34 PM

hi all
my mustang horn wont sound but makes a clicking or trying to work noise. it use to work fine. i did get it to work when i realized it was playing up. but it's not working more then working now. does any one have a solution to the problem.
thanks to all  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 03/13/13 06:51 AM

horns in SOME fords are wired like this...


the horn button in the steering wheel.. is open until you depress it.. then it grounds that wire ..

the horn relay usually has 3 wires on it...

a wire with battery positive.. usually fused..

a wire to the horn button on the steering column..

a wire to the HORN...

so when the horn button is depressed.. the positive voltage thru the horn relay coil now has a complete circuit and the relay closes.. this sends positive voltage to the horn wire.. causing the coil of wire in the horn to become an electro magnet.. this pulls on the steel plate.. as the plate deflects.. it breaks a contact and disconnects the internal coil of wire from power.. so the magnetic vanishes.. the diaphragm moves back and makes contact with the power connection again causing the circuit to be completed..flexing the diaphragm away from the contact to break the contact with power again.. this vibrating of the horn diaphragm is what you hear when the horn works..

right now.. you are just hearing the horn relay clicking...

find the horn... unplug the wire from it.. use another piece of wire with a female crimp terminal on it to hook up to the horn for this test...   touch the other end of the wire to the positive battery post..  the horn should honk now.. this would test the horn.. as water in the horn can damage them..

if the horn honks.. then the relay is probably bad...

if the horn does not honk...  then either the horn is bad.. or the ground connection between the horn and the body is bad.. or the ground connection between the body and the negative battery is bad..

sometimes the horn needs a light whack with a screwdriver handle to get the contact inside to connect...

let us know what you find...



edit...  MustangMan mark is completely correct... i did not realize that you were talking about your 65 mustang..   that is wired as mark describes...

i figured that since you were hearing a click only.. that you were just hearing the horn relay...

you could be hearing the horn diaphragm not breaking contact when the diaphragm moves...   whack it with a screwdriver handle while somebody is rapidly bumping the horn button on and off on and off..  that might free it up...

i know why ford went away from this simple double contact.. as when they have a metal horn ring in the steering column.. you can get zapped by the voltage from the horn vibrating if your hands are wet and some other part of your body is touching ground on the car..  usually getting in or out and holding on to the door handles..  or window frames.. my former 69 econoline got me a few times like that..  

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MustangMan
Moderator
Posts: 261
Joined: 08/11
Posted: 03/13/13 06:58 AM

Only the generator powered Mustangs used a horn relay (noted by a single contact in the steering column's turn signal switch. All alternator equipped vintage Mustangs (at least 65-70, never looked at a 71-73) do NOT use a horn relay at all and there will be two contact on the turn signal switch, making the horn button a simple pass through switch.

HTH...
Mark
.  
Mark Houlahan
Brand Manager
Mustang Monthly Magazine

1965 FFR Roadster 427W/TKO-600 5-speed
1966 Mustang 289-4V/C4 Auto
1968 Mustang 4.6L Three-Valve/5R55S Auto
1990 Mustang 306/AOD
2002 Explorer Sport Trac 4.0L V-6/5R55 Auto
2005 F-150 4x2 4.2L V-6/4R70W Auto

Post Reply
jlg2002
Guru
Posts: 1410
Joined: 03/08
Posted: 03/14/13 12:44 PM

Check the horns with voltage as Wayne's suggested.
If they sound the problem is with the wheel.
If they don't and just click, it means the diaphragm in the horn is stuck. Sometimes you can loosen the diaphragm nut a little to make them work .
If they don't even click they're bad.  

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hammoo46
New User
Posts: 7
Joined: 11/12
Posted: 03/16/13 10:48 PM

hi guys
i have done a bit of reading on the net and i have found that if i disconnect
one horn it works fine and so the other horn but together they don't work. i'm
under the impression that it's a amp thing with the car. the horns draw a lot of amps. i might have to replace a part i forget the name of it.
regards
jeff  

Post Reply
waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 03/17/13 07:19 AM

remove the steering wheel...


clean the contacts that ride in the grooves on the underside of the steering wheel..

clean the grooves on the steering wheel.. then use a thin coating of WHITE LITHIUM GREASE..

64 65 66 Mustang Turn Signal Switch ID  

Post Reply
cushman350
Enthusiast
Posts: 643
Joined: 07/06
Posted: 03/23/13 09:53 PM

I have revitalized stubborn old horns by removing them from the car and spraying vast amounts of your favorite solvent/lube into the large opening and carefully rotating the horn so that the lube travels toward the center and not out on your feet. Tap bang the body of the horn against something solid, rotate the other way and dump. You may have to spray again but more than not they will work again. A yearly spraying should keep the horn going.  

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hammoo46
New User
Posts: 7
Joined: 11/12
Posted: 04/01/13 04:11 PM

thanks cushman350
my horns are not too old by the look of them. i went for a drive the other day the horns worked but when i stop the car they don't. its a voltage problem or regulator problem i think. or some sort of electrical issue.  

Post Reply
waynep712222
User
Posts: 223
Joined: 04/13
Posted: 04/01/13 08:46 PM

by the way.... i don't recall what year your car is???

i have several wiring diagrams..

can you run the second half of this test??

part numbers 1, 2, 3, 4.... post some results by number...

Voltagedroptesting


1.............

2.,.........

3..........

4..........  

Post Reply
MustangMan
Moderator
Posts: 261
Joined: 08/11
Posted: 04/02/13 10:55 AM

If they work with the engine running and sound "sickly" or don't play with the car off it is simply a matter of amperage/load. My Mustang does the same thing with repro horns on it. It sounds fine when running (alternator charging) and if I shut the car off and try the horns an hour later (give or take) the don't sound as "strong". A week later and they sound "sick"...

If you like, you can rewire your horns through an aftermarket relay to get more power directly from the battery (same concept as the headlight brightening harnesses).

HTH...
Mark
.  
Mark Houlahan
Brand Manager
Mustang Monthly Magazine

1965 FFR Roadster 427W/TKO-600 5-speed
1966 Mustang 289-4V/C4 Auto
1968 Mustang 4.6L Three-Valve/5R55S Auto
1990 Mustang 306/AOD
2002 Explorer Sport Trac 4.0L V-6/5R55 Auto
2005 F-150 4x2 4.2L V-6/4R70W Auto

Post Reply
hammoo46
New User
Posts: 7
Joined: 11/12
Posted: 04/07/13 09:25 PM

my car is a 1965 coupe  

Post Reply
waynep712222
User
Posts: 223
Joined: 04/13
Posted: 04/08/13 08:17 AM

just a few days ago... a friend brought his 70 E300 over he just picked up....

he complained this horn barely worked...

i happened to have my remote starter switch laying on the work bench...

i unplugged the horn wire... clipped my remote starter switch to the horn and to the positive battery...

pushed the button to connect the horns directly to the battery.. i pushed and let up pushed and let up.. but i had my other hand over the horn opening so i was not blasted by the sound...

after about a minute of ON/OFF pulsing.. the horn was crystal clear as soon as i pushed the button..

you might want to test your horn..  without the rest of the circuit...

you might also if the horn is stiff funky...   pull the steering wheel off and clean the grooves on the back.. clean the contacts...

the turn signal switch diagram is misleading... the one with 2 spring loaded contacts, both of those seem to be for the horn... there are other later models that have contacts for the cruise control..


there is another thing to test...

do you have a set of JUMPER cables...???    hook BOTH Clamps on one end of the set to the NEGATIVE battery terminal ONLY... NOT THE POSITIVE terminal......

the other end of the clamps... hook one to something on the body thats not painted...  perhaps the bolts that hold the shock mounting brackets ...  the other clamp to the engine block...

then try your horn..  if it beeps nice and loud. then you have an ground issue...

grounds as i have posted before are HALF the circuit...

early mustangs need additional ground connections.. between the Negative battery cable and the body....    when original.... they seem to only be connected with a TINY wire from the back of the alternator to the mounting screw on the voltage regulator.... and from a braided ground strap at the back of the engine to the firewall....

there needs to be an additional connection.. on later models.. they had a TAB part way down the negative battery cable that was attached to the body. this is the body ground connection...

as far as i can tell... and hopefully somebody will set me right that this connection did not exist on the early cars.. as i know its on my 70 ranchero..  

do these tests.. prove the horn works when directly powered...

if it does not...

hook up the jumper cables and supply additional ground side connections.. for testing..

post what happens..  

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hammoo46
New User
Posts: 7
Joined: 11/12
Posted: 04/08/13 07:52 PM

the horns work when the car is running along the road. its when you stop at the lights or idle when the horns stops working.
i have done your multi meter test and it passed all the different stages.
would it be the voltage regulator. i have a newer version of that. not the original old coil type. thanks  

Post Reply
waynep712222
User
Posts: 223
Joined: 04/13
Posted: 04/09/13 05:03 AM

can you measure the battery voltage while you are idling and while you bring the motor up to about 1500 or 2000 rpms...

does it vary much???

14.1 to 14.6

sounds like its time to remove the steering wheel.. and clean the tops of the spring contacts on the turn signal switch and the contact rings on the back of the steering wheel.

you could also have an issue with circuits that supply voltage to the horn circuit..

while driving.. the alternator is supplying current to the car... at idle.. the current comes from the battery..  as the alternator does not put out as much current ...

this is going to give you a wildly ranging battery voltage...

can you break out your volt meter and try tests 1, 2, 3, 4 again...  but also start with the first half of the test.. how much charge your battery has after having the headlights on for one minute then turned off.. this is done engine off of course...

if the battery voltage is below 12.5.. use a 2 to 10 amp charger to add some additional charge ..

depending on the state of charge... 2 amps can go for 4 hours...  10 amps for 30 minutes only...

so.. results if you can..

engine off after the lights test voltage.. A______________

engine running, headlights on. .. positive to negative posts... 1.................

1A  at idle........      1B.... at 2000 RPM.....................

engine running..headlights on... negative post to the engine block..2..............

engine running headlights on...  Negative post to the body...3..............

engine running headlights on... engine block to the body...4.................

engine running headlights on... battery positive to the alternator output... 5..........

using  a single jumper cable from the positive and care not to touch it to anything on the body...

test to the cigar lighter center terminal  ______________


please post results..  before throwing any additional parts at this...

practice the tests i posted on another car that is working properly... or at least appears to work perfect..

why... because i have been fixing cars for a LIVING for over 30 years and these are the exact tests i use to trouble shoot problems.. before i replace just the bad parts..

i will put up a wiring diagram for a 65 as soon as i can colorize the horn supply circuit..

i found this 66 diagram and added some color to it..

power comes from the black and yellow wire on the starter relay..
thru the harness disconnect.. goes into a splice where it also continues into the fuse block.
from that splice it becomes and black and orange wire into the headlight switch. from another connector on the headlight switch.. it becomes a solid yellow wire where it connects to the turn signal switch connector..  

once in the turn signal switch.. thru one of the spring contacts.. across the steering wheel contact.. into the horn button..

from the other contact in the horn button back behind the steering wheel into the other spring contact..   it becomes a BLUE and yellow striped wire.. . back thru the turn signal switch connector.. thru the harness disconnect..  and to both horns..

can you UNPLUG and reconnect the connector from the back of the headlight switch a few times??
perhaps there is some corrosion..
you might also want to check for corrosion on the connector...

66 Mustang Horn Wiring Diagram Zpse93a29a1


here is an image of the starter relay... you can see the yellow wire twisted around the black and yellow wire.. the black and yellow powers this circuit..   the yellow wire goes to the other side of the amp meter...  and supplies power to other circuits in the car..

2012 05 04 11 14 11 11

the thicker black and yellow wire next to the red battery cable goes to the 3G alternator you can see in the lower right of the image above..  

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