Posted by #1 Son on March 22, 02 at 21:50:59:
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Friends,
Someone in the Suburban.Yahoo group asked for a circuit for a Warning Buzzer when the Parking Brake is applied. I have come up with the above. The basic circuit diagram came frome a pre-2000 models. For those models beginning with year 2000, the scheme of things still will works. However, the Parking Brake Warning Switch wire may NOT be Lt. Blue! Refer to your own circuit diagram or your actual wiring to accertain its color before doing the wiring.
As you can see, the solid state buzzer is from Radio Shack. Wire it up to point A and point B as shown.
Here is how it works:
1) The red wire is hot only if the ignition is on so that the buzzer works only if the Parking Brakes is applied AND the Ignition is on when you turn on the key.
2) Notice that the Light Blue wire is "hot" until the Parking brake is applied, shorting it to Ground, effectively completing the circuits for the Brake Warning Light and the Buzzer.
3) When the Parking Brake is NOT applied, the Buzzer's Black wire is also "hot"! But, since the buzzer is solid state, the internal "diode effects" essentially back biased the 12v so that it will not "cross feed" into the Ignition circuit.
One WARNING: Do NOT use a non-solid state buzzer!
Have fun doing it.
#1 Son
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