break up long pulse from relay

You could do without the diode if you want. It's just general good practice to add a supression diode to control voltage spikes that normally occur when a relay turns off, to avoid damaging sensitive electronic circuits being used to drive it. The cap acts as a buffer anyway. The arrow on the cap should have a marker like a (-) on it, and should point towards the leg that's negative. The other side is the positive and you'd then want to connect it towards the 12V source, which would be to the relay. The relay in the diagram just connects relay terminals 87 and 30 briefly when your lock input goes active, so you can hook up your buzzer with one end at 12V and the other end to the relay. If you want it to switch 12V rather than ground as shown, you would connect 12V to relay terminal 87 instead of ground.

petie-tl wrote: if I were to forget about the cap and resistor, and use a piezo buzzer (that has one red wire and one black) instead of the Horn(-) in the above diagram, would I need to add another relay? How would I wire up the piezo buzzer instead of the horn?

If you mean you want to forget about the momentary output business, and use a piezo buzzer instead of the horn to give you your audio feedback, then you could just connect 12V to the red of your buzzer, and the black directly to your lock (-) output control. I'm assuming your buzzer just needs 12V DC, and draws next to no power, so the lock output can drive it without any problem. Then you can just disconnect your horn and it wouldn't be as annoying.

I tried adding the piezo buzzer both of the ways pictured below but the buzzer does not sound.... which diagram is correct?? Diagram 1: Diagram 2: Here are the specs on the buzzer.... Pulsing Piezo Buzzer 1 red wire, 1 black wire Voltage range: 3.0-28VDC Current consumption: 12mA max at 12VDC Sound pressure level: 90dB min at 30cm/12VDC Resonant frequency: 2800 +/- 500Hz Pulse rate: 3.5Hz +/- 20% Could the buzzer be the problem? If so, what kind of buzzer should I be using??petie

'98 Acura TL 3.2

Either one should work- Do you hear the buzzer when you just connect it up directly to 12V and ground? If your parking lights flash, it should buzz, unless your buzzer is busted or was connected backwards.

You described your buzzer as a "Pulsing Piezo Buzzer"; It may be set up to output a beep-beep-beep sound, so it might take a bit of time before it starts sounding. Depends on how the internal oscillator circuitry is designed. If you just touch the 12V power briefly to your buzzer briefly, does it start sounding off immediately as soon as you make contact? If not, then you'll want to get a continous sounding buzzer for this application.

Got a regular (not pulsing) piezo buzzer and it works!! Thanks!!!!petie

'98 Acura TL 3.2