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Unknown Part - Help

Old Dec 22, 2017 | 03:03 PM
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Default Unknown Part - Help

Does anyone know what this is?

I have a 1968 C3 convertible. It was on the engine side of the firewall, glued to the top of my heater blower cover. I have taken the top off of it for the photo...


Mystery Part
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Old Dec 22, 2017 | 03:09 PM
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Might want to see where the wires lead or go to via a wiring diagram. My best guess would be some kind of homemade car alarm.
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Old Dec 22, 2017 | 03:42 PM
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I Googled Ademco. Its an alarm system from Honeywell. I'm thinking its a magnetic switch like you would see on a door or a window in a home alarm system.

Last edited by drwet; Dec 22, 2017 at 03:43 PM.
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Old Dec 22, 2017 | 03:52 PM
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It's not stock if that's a concern.
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Old Dec 22, 2017 | 05:41 PM
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Originally Posted by drwet
I Googled Ademco. Its an alarm system from Honeywell. I'm thinking its a magnetic switch like you would see on a door or a window in a home alarm system.
I agree but there must be the other half of it somewhere.
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Old Dec 23, 2017 | 07:52 AM
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follow wiring it must go to door switches or a horn somewhere
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Old Dec 23, 2017 | 08:22 AM
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Originally Posted by henrikse
follow wiring it must go to door switches or a horn somewhere
Electric door lock.
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Old Dec 27, 2017 | 06:41 PM
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Default I found another one!

I found another one of these mystery switches in the tunnel, mounted near the emergency brake. It looks like these switches are part of an alarm system. I have included the alarm system photo with this post as well. Is this an aftermarket alarm? It is not functional so does anyone know if I can cut the wires and remove it without messing up the ignition function?

Additional switch found



alarm box found in the jack compartment
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Old Dec 27, 2017 | 06:43 PM
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Default Here's another mystery part on my 68 C3

Found this behind the passenger's dash panel. Any guesses as to what it is?


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Old Dec 27, 2017 | 06:52 PM
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Bubba's had been busy on this one, no?
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Old Dec 27, 2017 | 07:02 PM
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I'd wager it's a car alarm. I've seen guys use that style of magnetic reed switch as a hidden shutdown/starter kill system too. The Magnet (on the left of the picture), has to be placed in exactly the right spot or it won't crank.
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Old Dec 27, 2017 | 07:12 PM
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If the car goes above 50 mph, it arms itself; if it then falls below 50 mph.... You won't like it....






Adam

Last edited by NewbVetteGuy; Dec 27, 2017 at 07:12 PM.
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Old Dec 27, 2017 | 08:30 PM
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Originally Posted by Lagonia
Bubba's had been busy on this one, no?

Oh yes he was!
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Old Dec 27, 2017 | 08:34 PM
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Adam, the video won't play that you posted. Does any Vette go below 50?
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Old Dec 27, 2017 | 08:35 PM
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TimAT... so you are saying that the clear plastic switch is part of the car alarm? If it is, I'll remove it.
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Old Dec 27, 2017 | 10:16 PM
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The clear plastic piece is either a primitive motion sensor or a relay.

If you remove it- just make sure it was not used to interrupt your starter.

Fairly common back in the day to put a relay in line to disengage the starter wire to keep it from being stolen.

Richard
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Old Dec 27, 2017 | 10:56 PM
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Originally Posted by Richard454
The clear plastic piece is either a primitive motion sensor or a relay.

If you remove it- just make sure it was not used to interrupt your starter.

Fairly common back in the day to put a relay in line to disengage the starter wire to keep it from being stolen.

Richard
Thank you so much!!!
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To Unknown Part - Help

Old Dec 27, 2017 | 11:27 PM
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I agree with Richard454- either a motion switch or a relay- I'm leaning toward a relay looking at the schematic on the side of it.
Find the 10ga Purple wire from the starter (inside terminal) and follow it back to either the clutch safety switch (manual trans) or the neutral safety switch (auto). I'll bet it somewhere feeds to that relay, maybe thru the black alarm box.

The original wiring diagram for your car will show how the wires were connected by the factory, and may lead you to where things where cut to install that alarm system.
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Old Dec 28, 2017 | 05:49 AM
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could be a ejection seat relay for the driver stealing the car

Last edited by lvmyvt76; Dec 28, 2017 at 05:49 AM.
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Old Dec 28, 2017 | 08:56 AM
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Originally Posted by TimAT
I agree with Richard454- either a motion switch or a relay- I'm leaning toward a relay looking at the schematic on the side of it.
Find the 10ga Purple wire from the starter (inside terminal) and follow it back to either the clutch safety switch (manual trans) or the neutral safety switch (auto). I'll bet it somewhere feeds to that relay, maybe thru the black alarm box.

The original wiring diagram for your car will show how the wires were connected by the factory, and may lead you to where things where cut to install that alarm system.

Thanks for the guidance. I'll check it out.
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