Wireless Lock Tone

Posted on Feb 6, 2014

When I got the car I was relieved that it didn`t `chirp` or blare the horn every time I locked or unlocked the doors. Let`s face it, there are times when we don`t want our comings and goings announced in such a tactless manner. Still, I found that in the daytime, when walking away from the car, or after forgetting until I`m some distance away, I c

Wireless Lock Tone
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ould not tell if the car was locking or unlocking. I found on the crossfireforum. org website an idea to install a device that gives out a gentle tone that can be heard from a short distance and does not announce the locking or unlocking like the opening of a Broadway musical. The circuit I designed has a single-pole, double throw push-button switch. In one position, the buzzer in the circuit quietly beeps. In the other position, the lamp in the circuit flashes. The reason for the lamp is to provide a diagnostic function to aid in troubleshooting if problems develop. I mainly put the switch in to provide an easy way to disable the beeping sound if for some reason I didn`t want it to operate. I removed the relay and wrapped the wires around the 85 terminal (positive) and 86 terminal (negative). After shaping the wires, I removed them and put some solder on them to help them keep their shape. Then I replaced the wires on their respective terminals, and reinstalled the relay in its socket. Here is a view of the wiring coming from the relay in the upper right corner of the picture. Black is ground and white is positive. Note the thicker red wire coming off the fuse bank. This is the switched positive lead that goes to the auxiliary fuse box I assembled and installed in support of my stereo install. I took this opportunity to route the red stereo wire and the leads for the buzzer through a rubber port provided for this purpose....

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