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71 Roadrunner key in buzzer

Rusty

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Finally got the key in buzzer to work only problem is it stays on when the engine is started, ignition switch?
 
The key in buzzer on 71/73s gets a constant positive from batt. Is actually the same power source than the horn: violet wire on fuse box provision for the horn relay/key in buzzer. Its activated by ground just with driver side door is open AND key is in. Both stages must be activated to be able to buzz.

rest of wires are…
green with red traces—-positive to horn
1 black on the three wires group—-horn switch ground
the other black wire apart from the rest—ground coming from key in sensor/switch.

sooo, that’s what I can say to begin the diagnosis.
 
Thanks that helps, Schematic shows a diode ?
 
This switch could be broke or maybe a bad door jamb switch..

FFB7BA59-E89C-4439-9C17-090439090AE7.jpeg
 
Where is this one located?
 
Oh hell I just replaced the turn signal/horn/flasher
 
It never worked in either of my 70’s. The reverse lockout stuff was missing as well. I would have eliminated that stuff too.
 
The diode is used on 70s, since it works diff, being sourced by positive coming from the lighting circuit instead ground.

This is the basic diagram I made to show how it works these two buzzers related to the door ground on 71/73s

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In the column right below ignition switch..
Just to support the comment ( but not the switch, the cylinder )

dsc_0118-jpg.jpg

sometimes hold by just one screw and a pin, sometimes two screws. But both interchange

the ign switch gets a lever which pushes the switch when key is in to close the path to ground (as far door is open) and feed the buzzer.

25FDF7EA-7393-464B-96D3-A13D03649C20.jpeg
 
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When my key is half way in the buzzer goes on when I start the car the buzzer stays on except for one time today it worked as it should. Does that sound like a bad switch?
 
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Well… it could be. They are not hard to find NOS and doesn’t use to be really outrageously expensive, although prices have been raising up lately. I guess because stock is going down.
 
Well… it could be. They are not hard to find NOS and doesn’t use to be really outrageously expensive, although prices have been raising up lately. I guess because stock is going down.
They have gone up between $100-200 now which is a big jump..
 
Ok, I just checked eBay… old ones are on that rate, over $100. The older, the more expensive in fact (the ones using two screws to attach, next ones are with an alignment pin and one screw).

There are some others below that price with red wires and a plug. They are exactly the same pieces but just using their own plug, so not running through the ign switch plug. Just remove the plug and insert into the ign switch plug and done.

There are some other for later cars, which got blue wires and diff terminals and plug end. They work and fit exactly the same with diff color wires and for the terminals you can splice the terminals or even the wiring itself just leaving the switch from the old one… or just get the standard molex terminals and attach it into the blue wire ends. These switch are still below $50 rate.

Becarefull with the blue harness ones, because some even laters got a diff bracket shape and won’t work. But the late 70s are same shape.

some PNs to search
2947488
3747116
4131522

That’s talking about NOS on eBay… now searching on boards you can get maybe better prices and even good used. I have a couple ones used and in working order, but I’m 6K miles from them right now.

now, you can also run to JY and try to find one from any 70’s Mopar? That’s another option. If is a pick and pull JY is a lot of work for just the switch thought, but will depend on you LOL.
 
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