My car has a after market Carrera wheel. Horn tests good on a battery, power is there to the horn lead, ground test good to connector #5, when I ground the horn pluncher wire to the wheel the horn sounds , weak, and the wire sparks...any ideas?
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Full Version: Horn Problem
Bad horn.
No horn tests good, and the new horn didn't work.
He said horn tests good on battery. Has to be wiring. That sounds too obvious, I know. Sorry.
This is where my first 10-second shot would be running jumpers from the hot wire and ground point in the column to a horn on the side and see if it works differently. Process of elimination, then wire tracing.
This is where my first 10-second shot would be running jumpers from the hot wire and ground point in the column to a horn on the side and see if it works differently. Process of elimination, then wire tracing.
I would be concerned that in your picture, the wire from your horn relay to your horn button is red. On my car and on the Pelican wiring diagram, the wire from the horn button, H, to the horn relay, J4, is shown as brown with a white stripe . What color is the wire at pin 85 on your horn relay, should be brown with white stripe? If it's the same red as at your wheel, check it's continuity to the horn button. If that wire is correct, then check continuity on the black wire with yellow stripe that goes from the pin 87 on the horn relay to power the horn. The brown wire on the horn itself is ground.
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I believe its a grounding issue behind he wheel.
Take it off and take a look at the contact that the red wire is using on the metal ring on the back side of that wheel hub.
That is how it gets its ground, so it needs to be a great connection, and super clean.
its two rings, one wire from below (brown/white) to the lower ring, and your red lead is connected to the upper ring.
rich
Take it off and take a look at the contact that the red wire is using on the metal ring on the back side of that wheel hub.
That is how it gets its ground, so it needs to be a great connection, and super clean.
its two rings, one wire from below (brown/white) to the lower ring, and your red lead is connected to the upper ring.
rich
QUOTE(r_towle @ May 22 2017, 03:50 PM) 
I believe its a grounding issue behind he wheel.
Take it off and take a look at the contact that the red wire is using on the metal ring on the back side of that wheel hub.
That is how it gets its ground, so it needs to be a great connection, and super clean.
its two rings, one wire from below (brown/white) to the lower ring, and your red lead is connected to the upper ring.
rich
appears to be a short there,maybe the contact ring isn't right,but we don't know if its a stock one or Lecarra one depends on the boss used of course.Just fitted momo adaptor and other aftermarket wheel,touch the horn wire to the wheel and all is load and clear.
QUOTE(oakdalecurtis @ May 21 2017, 06:15 PM)
I would be concerned that in your picture, the wire from your horn relay to your horn button is red. On my car and on the Pelican wiring diagram, the wire from the horn button, H, to the horn relay, J4, is shown as brown with a white stripe . What color is the wire at pin 85 on your horn relay, should be brown with white stripe? If it's the same red as at your wheel, check it's continuity to the horn button. If that wire is correct, then check continuity on the black wire with yellow stripe that goes from the pin 87 on the horn relay to power the horn. The brown wire on the horn itself is ground.
Click to view attachment
Thanks for reply, I don't think 1970's have a relay. Here's a photo of the contact ring.
QUOTE(porschetub @ May 21 2017, 08:49 PM)
QUOTE(r_towle @ May 22 2017, 03:50 PM)
I believe its a grounding issue behind he wheel.
Take it off and take a look at the contact that the red wire is using on the metal ring on the back side of that wheel hub.
That is how it gets its ground, so it needs to be a great connection, and super clean.
its two rings, one wire from below (brown/white) to the lower ring, and your red lead is connected to the upper ring.
rich
appears to be a short there,maybe the contact ring isn't right,but we don't know if its a stock one or Lecarra one depends on the boss used of course.Just fitted momo adaptor and other aftermarket wheel,touch the horn wire to the wheel and all is load and clear.
Thanks, better photos here;
http://forums.pelicanparts.com/porsche-914...ring-wheel.html
Up through 72 or 73 the horn does not have a relay. Power gets sent to the horn full-time, and the wire in the center column provides the ground.
Getting a spark from the connection says that some wiring is very funky, but I don't know how that wire is run. Trace it and look for connections. Those could be weak or dirty.
--DD
Getting a spark from the connection says that some wiring is very funky, but I don't know how that wire is run. Trace it and look for connections. Those could be weak or dirty.
--DD
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