The Ford Barn

Ron Barber · 09-09-2010, 09:01 PM

Horn picking up a ground and runs continuous. Has anyone had this problem? The horn works great and checks out ok. But when grounded to the frame it will run and heat up at times.

Mike V. Florida · 09-09-2010, 11:45 PM

The horn works by passing the voltage through the horn and up to the steering wheel where it is grounded. I would check the bottom of the steering box where the light and horn connections are made. If you have a reproduction harness anything can happen.

Ron in Quincy · 09-10-2010, 01:21 AM

Some of the poorer quality wiring harness terminal block horn connection will cock sideways and ground out in the switch.

Ron

Bruce of MN · 09-10-2010, 05:56 AM

Mine was doing that and the insulating washer between the frame and one brush holder was missing. I may have left it out before while trying to make it work.

I found it by using my ohmmeter probes at each point of the circuit until I found it.

Mitch//pa · 09-10-2010, 07:12 AM

1.disconnect the wires from the horn
2. take a 12 volt test light and connect it between the leads that go to the horn. it should flash as your pressing the horn button. this confirms your circuit is working properly
if that ck's out then you may have a problem inside the horn

http://www.pasetta.net/Model%20A%20T...ingdigram.html

Tom Wesenberg · 09-10-2010, 12:51 PM

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Every time I see that happen it was because one of the brush holders was grounded. There MUST be an insulating washer on each side of the motor frame. So, you have the brush holder, insulating washer, motor frame, another insulating washer to fit in the countersunk hole, then the mounting screw. You need this on BOTH brush holders.

You can make an insulating washer from thin fiberboard, or even an old credit card. Something like the cardboard from a cereal box WON'T make a good insulating washer.

09-09-2010, 09:01 PM	#1
Ron Barber Member Join Date: Jun 2010 Location: Glen Gardner, New Jersey Posts: 57	Model A horn Horn picking up a ground and runs continuous. Has anyone had this problem? The horn works great and checks out ok. But when grounded to the frame it will run and heat up at times. __________________ Ron

09-09-2010, 11:45 PM	#2
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Model A horn The horn works by passing the voltage through the horn and up to the steering wheel where it is grounded. I would check the bottom of the steering box where the light and horn connections are made. If you have a reproduction harness anything can happen. __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

09-10-2010, 01:21 AM	#3
Ron in Quincy Senior Member Join Date: May 2010 Location: Quincy, CA. Posts: 1,708	Re: Model A horn Some of the poorer quality wiring harness terminal block horn connection will cock sideways and ground out in the switch. Ron

09-10-2010, 05:56 AM	#4
Bruce of MN Senior Member Join Date: May 2010 Location: VA Posts: 1,410	Re: Model A horn Mine was doing that and the insulating washer between the frame and one brush holder was missing. I may have left it out before while trying to make it work. I found it by using my ohmmeter probes at each point of the circuit until I found it.

09-10-2010, 07:12 AM	#5
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: Model A horn 1.disconnect the wires from the horn 2. take a 12 volt test light and connect it between the leads that go to the horn. it should flash as your pressing the horn button. this confirms your circuit is working properly if that ck's out then you may have a problem inside the horn http://www.pasetta.net/Model%20A%20T...ingdigram.html

09-10-2010, 12:51 PM	#6
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Model A horn Sponsored Links (Register now to hide all advertisements) Every time I see that happen it was because one of the brush holders was grounded. There MUST be an insulating washer on each side of the motor frame. So, you have the brush holder, insulating washer, motor frame, another insulating washer to fit in the countersunk hole, then the mounting screw. You need this on BOTH brush holders. You can make an insulating washer from thin fiberboard, or even an old credit card. Something like the cardboard from a cereal box WON'T make a good insulating washer.