Horn and turn signal question

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Joined
May 15, 2011
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Location
PA
My Car
1971 Mach 1 Mustang
Hey guys. The gentleman I painted the 71 for has brought his car back for some work. He needs the front turn signals in the valance looked at and the horn. So I had a couple questions before I get too crazy on it.

1st    We replaced the front turn signal housings when we repainted it. They are plug and play. With headlights off, front turn signal will blink. With headlights on the light is very bright but will not blink. Could the bulb just be in backwards?? Making both filaments light up when headlights are on?? Not sure if it was like this before we swapped them out??

2nd.  He has an aftermarket steering wheel in it. The horns sound like crap and only blows properly once in a while. Depending how you push down on the button. Do you guys think the ring inside just need adjusted to make proper contact with the contacts??  I ran 12 volts straight to the horns and they work fine. The button inside the wheel just isn't making contact properly I believe to get the full 12 volts out to the horns. If you push the button down at an angle the horns blow properly. what do you guys think??



 
first thing to do is for u to do some research on the horn assemble for that car. he just may have installed the wrong one. when i did my '66 fairlane there were something like 3 kits but only one was correct. with the turn signal it might have just said good bye and really needs replacing. if u need to replace the turn sig sw, do yourself a favor and remove the drivers seat.

 
I think you are right on the mark with your diagnosis of the parking lights. Sounds like both filaments are lit when the parking lights are turned on with or without the headlights being on, and what is blinking when the parking lights are off is only the single (dimmer) filament. It's either the bulb is reversed or if the sockets were replaced or rewired and the two power wires are reversed. It's not a ground problem since both filaments will light albeit incorrectly.

Same with your suspicion on the weak ground for the horn. Try cleaning up the ground contact areas on the button, both sides of the wheel and possibly the column.

 
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It sounds like you have a ground problem with the lights in the front. I'll bet that if you turn the headlights and turn signals on, and run a wire directly from the negative post on the battery to the turn signal housing/ground the turn signals will work. If that isn't the problem it'll be a voltage supply problem, with bad or corroded connecotrs.

It's been my experience that the horns for aftermarket steering wheels range from fair to bad. Our cars use commutator rings and brushes to provide connection from the horn assembly to the wiring in the steering column. The commutator rings have to be clean and lightly greased. A common problem is that the commutator rings are too far from the brushes (which are connected to the turn signal switch assembly), and sounds like it may be your problem. Make sure the steering wheel hub is installed properly and seated down all the way on the shaft. It's also possible the horn button is part of the problem. People use tape to hold the horn button spring in place while installing the button and it can interfere with the horn button making contact. There is also a wire that runs from one of the rings to the horn button grounding plate that can be loose.

 
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Thanks for the replies fellas. I have figured out the turn signal lights.

We replaced the entire housing when we painted the car. The owner bought the replacement lights from CJ pony parts. They were made to plug directly into the original harness plug. Well they F*cked up when they made them. They have the 2 power wires in wrong place. When running lights are on both filaments light up. When running lights are off just one filament will light up when turn signal is on. So I just need to swap the two power wires and all will be solved with the lights!! Another reason I will never buy from CJ pony parts!! So many things that were messed up with this build because of their junk. OMS will always have my business.

 
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