Author Topic: DIY Lights on Warning Buzzer  (Read 5376 times)

Offline JMallows

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DIY Lights on Warning Buzzer
« on: 10 April 2007, 19:19 »
Equipment needed:
·   12V Buzzer
·   Changeover Relay (12V)
·   Cross head screwdriver
·   Wire
·   Small flat head screwdriver.

1.   Remove the under dash tray from under the steering wheel. Undo all the screws around the outside with the crosshead screwdriver. There’s about five or six.
2.   Remove the driver’s door switch. Easy, undo the single screw holding it to the body, then pull out. Be careful not to shut the door with the switch out, it bends it a bit. You don’t have to remove the wire going to the back.
3.   Remove the heated rear screen switch. Set the switch to the on position, and lever it out from the bottom using the flat head screwdriver. There is a little slot for the driver to fit into. Again you don’t need to remove the wires.
4.   Get your buzzer. You need to test if it’s electrolytic, connect the wires to something 12V, e.g. the interior light connector (take out the light and stick the wires into the red and brown wires on the connector) if it buzzes good, then swap the wires over. If it still buzzes then it will work however you wire it, if not then you need to remember which is negative, and which is positive. They should be red and black, but you never know!
5.   The next step is to wire in the relay. I used Maplins N17AW relay, which cost me £1.91, so pretty cheap! The following diagram shows the pin-out for the relay.



6.   Work out which pin is which by using the diagram, basically pins 1 and 16 are opposite each other, but are also spaced further apart than the others. You can test that you have pins 1 and 16 by applying 12V to pin 1 and pin 16 to earth. The relay will click when 12V is applied, and then click again when the power is removed.
7.   A small piece of veriboard is required here. I used JP52G from maplin again. Any size board will do, as long as the buzzer and relay both fit onto it.
8.   Solder the relay in place. This needs to be done in the correct manner. Pins 1 and 16 should share the same line, and this is the proper orientation of the board. Solder the 8 pins in place, but not right at the edge of the board, wires need to go on both sides of the relay. Now, a drill bit (or similar) needs to be used to cut the copper tracks across the board. This is done in between the relay, so that pins 1 and 16 aren’t connected. This needs to be repeated for all 4 sets of pins. The drill needs to remove all the copper from the track, but doesn’t need to make a hole in the plastic. This is shown below. A cross indicates where you should cut the track.



9.   Next up is to secure the buzzer to the board. This is best done with some glue, though screws can be used, as long as the screws don’t interfere with the electrics of the board…
10.   The relay needs to be powered only with the ignition. Take one lead from earth (the earth claw or wherever) and attach it to pin16, and then take a lead from ignition live (back of the fuse box) and connect it to pin 1.
11.   Take a wire from pin 4 or 13 (whichever side of the relay you want to use) and attach it to the door earth. Take the wire from the relay and route it to the right hand side of the car. You have to pass it through the sound deadening and into the cavity behind. You should then be able to pass it through the hole for the door switch. So, you know have a wire running from the relay to somewhere near your switch. Attach the wire to either, the brown wire going to the door switch, or to the connector that the brown wire connects to. As long as it doesn’t connect to the metal that the screw touches, it’s fine. Now pop the door switch back in and screw it up.
12.   If you used pin 4 then pin 6 needs to go to the buzzer, and if you used pin 13 then pin 11 needs to go to the buzzer. Connect the wire from either pin 11 or 8 to the negative side of the buzzer. The positive side needs to go to something that is live with the lights. I used the heated rear screen switch, though anything can be used like the headlight switch, or the headlights themselves. 
13.   Take a wire from the positive side of the buzzer up through the dash to the heated rear screen switch. You need to attach it to the positive connector for the lights. In mine it was the blue/grey wire, at the top right as you look at the connector. Now attach the red wire from the buzzer to this wire, either, splice the wire on, or much easier, poke the wire through the hole on the switch. When you plug the connector back on, it will be fine. Stick the switch back in.
14.   The final full diagram is shown below, to check that yours is wired correctly.



15.   Reattach the under dash tray.
16.   Shut door.
17.   Turn on lights. There should be no buzzer sound, open door and buzzer will sound. Shut door and the buzzer will stop. Also, with the door open, the buzzer should sound, and then stop when the ignition goes on. If you have a delay light it will buzz until the light goes off.

Any problems, suggestions etc... let me know :) Let me know if this makes any sense!
« Last Edit: 10 April 2007, 19:26 by jmallows »


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Offline JMallows

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Re: DIY Lights on Warning Buzzer
« Reply #1 on: 10 April 2007, 19:26 »
Also, it doesnt matter which way round you get the ignition live and earth, i have shown them both ways in the two diagrams, which is sure to confuse, but it will work both ways!!!

You also dont HAVE to use the board, you could just use solder to connect the wires directly to the relay pins, but they are very small and delicate, and securing them to a board, and then bolting the board to the car is pretty sensible :)


A clever person solves a problem. A wise person avoids it.