Is It Locked?

[Berisford]

I've recently bought a new Yaris Icon+ CVT version. I like its simplicity compared to many a modern car but I do miss having a security (LED) flashing to let me know, from a distance, that it's secure. It wouldn't have been a deal breaker but I never for one moment thought that the Yaris would be without the simple flashing beacon that's been fitted to motors for about 20 years now, seems a bit mean not to include it?

[Raistlin]

Use this:

http://www.maplin.co.uk/p/security-flashing-led-un42v

How can I make this led flash when ignition is off but not when its on?

Wire like this:

Connect the negative side of the led to a ground in the car and the positive side to pin 87a on an automotive relay, then connect pin 85 to a ground in the car and pin 86 to the accessory wire.

[Berisford]

..........yes, an option, but those aftermarket Maplin type things always flash too fast and give the game away. Slowing the flash rate down is near on impossible, plus, and more importantly, that still wont tell me with just a glance as to whether or not the car is locked.

[Raistlin]

Connect it to the door lock wiring for the positive and you can use a resistor to slow down the flashing speed.

[Berisford]

Unless I'm missing a trick, the resistor thing doesn't do the business, it can dim the brightness but doesn't slow the flash rate and I've tried a few combinations of LED/resistor.........there are a few opinions and 'how to' on the web but they're all a bit too convoluted and complicated without any really successful results......

[Raistlin]

Instructions

1 Obtain an electronics-flasher hobby kit that uses a 555-timer chip. Build the circuit according to the instructions given.

2 Locate the 555 timer on your circuit board or schematic. Now locate the timing resistors (R1 and R2) and timing capacitor © that are connected to the 555-timer component. Look at the components connected to the 555 timer: between pins 8 and 7 for R1, between pins 7 and 2 for R2 and between pins 6 and 1 for C. Write down the value of the resistors and capacitors. Use the values for R1, R2 and C given on the schematic or the electronic parts list, or the value that is written on the resistors and capacitor components.

3 Calculate the frequency of operation using the formula given in the 555-timer data sheet. Use 1000 ohms for R1, 2000 ohms for R2 and 10uF (0.000010) for the capacitor C. Multiply the value of R2 by 2, then add that to the value of R1. Next, multiply the result by the value of C. Finally, divide 1.44 by the last result. Verify your calculation with the formula:

f = 1.44/(R1 + 2R2)C = 1.44/(2000 + 2*2000)0.000010 = 24 blinks per second

Select a higher value of R1 to lower the blink rate. Use 20,000 for this example. Calculate the blink rate to be 0.6 blinks per second, or 6 blinks every 10 second.

[MikeSh]

You could wire the LED without a relay. Find a permanent feed (eg. interior light) and an ignition or acc fed device that is normally that can sink a little current (eg. DRL (lamp, not relay), fuel pump, maybe radio). Connect +ve of LED to permanent feed and -ve to the 'switched' 12V line. When the ignition is off the current goes through the LED to the dead switched line and to earth via the lamp or whatever. When the ignition is on the LED has 12V on both sides, so no current flows and it is off.