led flasher resistors

[Peter-C]

My setup is that the front and repeaters are ordinary lamps but the back are leds. It appears that I need resistors wired in parallel with the leds. Does anyone know if they go as close to the lamp as possble or can you connect them anywhere in the loom as all of the lights are in parallel. Hope it makes sense.

Cheers

Peter

[mark]

My car is the same using led at the rear, I never really thought about location and fitted them to the inside of the rear tub quite close to the actual lights, I would imagine they will work the same regardless of location

They do get quite hot though so make sure they are in an appropriate position wherever you put them

[Peter-C]

Cheers Mark

[alga]

Hey, the resistor need needs to be in series with the LED, not parallel! LEDs typically work with a 2-3V voltage, depending on type. The resistor is needed to take the rest of the voltage. http://ledz.com/?p=zz.led.resistor.calculator

[davedew]

The resistor is wired in parallel as it is there to apply the extra load that the relay needs to see to flash correctly, not drop the voltage to the led's.

The other option is to buy a dual load indicator relay. These have a fixed flash rate and will work with either led's, bulbs, or a mixture.

Something like the below. This should be suitable for use in the standard Sierra wiring setup.

http://www.ebay.co.uk/itm/LED-FLASHE...em5d2f4 c7b2f

[rich]

im using a 3 pin led flasher unit got off ebay for about £5, just plug it in
make sure the pin configuration is the same, some are different

[Peter-C]

Just tried one connected under the scuttle WORKS FINE !!!

Thanks lads

[robo]

Originally Posted by davedew

The resistor is wired in parallel as it is there to apply the extra load that the relay needs to see to flash correctly, not drop the voltage to the led's.

The other option is to buy a dual load indicator relay. These have a fixed flash rate and will work with either led's, bulbs, or a mixture.

Something like the below. This should be suitable for use in the standard Sierra wiring setup.

http://www.ebay.co.uk/itm/LED-FLASHE...em5d2f4 c7b2f

I reckon that relay is the kiddie. Its the proper job and will keep the legal 60/120 flashes per min where they belong. not saying dont use resistors but all the guess work is gone using that relay.

Bob

[Not Anumber]

Standard car flasher relays are current / thermal dependant. The rate at which they flash is determined by the wattage load of the indicators. If one of the bulbs blows (or is replaced with a LED) the thing flashes at an 'alarming' rate. Alarming being the right word because it used to be considered a useful thing to let motorists know they had a blown bulb - before the days of buld failure warning circuits.

This arrangement was of course no use for anyone towing a trailer or caravan and the fix was a simple one- to use a slightly different type of flasher relay, one that wasn't dependant on bulb load but would continue to flash away at a fixed (MOT compliant) rate however many bulbs were connected to it.

These are still available and shouldnt cost £ 14 - something like this would do the job perfectly well:

http://www.ebay.co.uk/itm/Electronic...em56482 92196

Using a standard flasher relay with a parallel resistor is of course another way round but frankly not the best. The resistor will heat up quite a bit as it effectively has the whole power of the battery accross it (not something i'd want next to the wiring loom in my car, near the fuel tank etc).

Doing it the right way avoids the risk of components overheating and reduces the load on the battery and alternator.

[ayjay]

Just sent for one of those to stop my flashers going banananananas.

Worth a punt for £1.38 inc pp (well you never know do you-it may have something inside the plastic case)

Ill let you all know how I get on-and if it works.

BTW another step closer-Arf pointed out that my servo vac pipe was still unblanked causing my engine to stop after about 5secs---Ive now got a proper vroom vroom. Vid cam charging --appropriate music chosen --car will emerge on first dryish day( well I dont want it to get wet do I)