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LED Lights

Discussion in 'Electrical' started by mudtiera, Jun 29, 2010.

  1. mudtiera

    mudtiera Member

    Hey, just gone LED tail lights but now they flash faster then normal, like if I had a glob out, I put a new eletronic flasher unit in and still does the same, is there anything I can do to put back to normal??? Thanks in advance. Phill
  2. Split pin

    Split pin New Member

    No not really. As the led lights take less amperage your flasher unit is sensing that a globe is out. You can purchase L E D globes that will fit into your other indicators and that should solve your fast flash problem.
  3. Grey Ghost

    Grey Ghost 4x4 Earth Contributer

    May need to fit a ballast resistor in series with the led globe to slow it down. Chances are if it is flashing to fast it is because the LED is getting more voltage than it needs.
  4. Cuvier100

    Cuvier100 Member

  5. Alien d2

    Alien d2 4x4 Earth Contributer

    Slip over to Jaycar,
    (From their site)
    Shop 1/50 Queen Street 2560
    Ph: 02 4620 7155
    Fax: 02 4620 5866

    Trading Hours
    Mon-Fri: 8.30 - 5.30
    Thu: 8.30 - 7.30
    Sat: 8.30 - 5.00
    Sun: 10.00 - 4.00
    Map: Campbelltown
    New South Wales, Australia."

    They should be able to help you out.
    You need a flasher can to suit the LED's.
    They may have a inline ballast unit you could use.
    I'm sure they would have seen it before, our local outlet seem quite good.
  6. bmurray2250

    bmurray2250 4x4 Earth Contributer

    The flasher unit sensors on current draw which is caused by the resistance of a bulb. There are LED replacements which has this feature added. The other choose it to replace the flasher unit that designed for LED bulbs
  7. Pure Yobbo

    Pure Yobbo Moderator

    Yep current draw is the problem and they think you have a bulb out somewhere hence flashing quicker.

    I read somewhere if you leave one or two of the bulbs as the original type (eg the indicators in a bullbar) they draw enough cuttent to flash ar normal speed again.

  8. Davidman

    Davidman 4x4 Earth Contributer

    Like some of the others who have posted, I have some LED 'fast flashing' indicator issues. I have replaced both sets of lights in the rear bar. Have actually removed the rear bar in readiness for a custom one, and installed stop/tail/indicator LED's on both sides. There are also side indicators on the rear, indicators on the side of the vehicle just in front if the front doors and obviously the front indicators. That means there are still 6 with normal globes. These are not drawing enough for the system to think all is okay. Are there any other options as opposed to different flasher units ( is there a flasher unit that can be used for combination LED's and globes ), or replacing the other 6 globes with LED's.

    Another question, does it matter that it is flashing at twice the speed, apart from the flasher unit and remaining globes having their life halved. Possibly doesn't comply with ADR's, but would you get booked over it ?
  9. olcoolone

    olcoolone New Member

    Your flasher can is not seeing the right load due to the LED replacement, it is much the same if you have a blown indicator globe on the rear making the front one flash faster.

    Flasher cans use the resistance of the globes to set the flash rate.

    What you can do is fit an LED flasher can or you can buy a resistor for the LED light to increase the resistance of that circuit.

    Have a look here Bright Light Auto Parts - LED Lamp accessories
  10. millsy

    millsy 4x4 Earth Contributer

    I would try soldering a 5 Ohm, 30 watt resistor in parallel with each LED tail light.

    LEDs always have an inbuilt protective resistor connected in series with them, since too much current through a LED will 'blow' it. So each LED in the tail lamp will have its own protective resistor. With the circuits I used to 'play' with I used to use 220 Ohm or 330 Ohm protective resistors. So the flasher unit is sensing a high resistance when it trys to give current to the LED tail lamp. I guess this has a simillar effect on the flasher as the infinite reistance of a blown normal bulb.

    So to make the flasher think it is still providing power to a 12V 20W bulb, about 2 Ohms say, you could try putting a 5 Ohm resistor in parallel with the LED unit. Without knowing the resistors, and how many, in the tail unit, I cannot calculate the exact shunt resistor required. I think a 5 Ohm resistor would be a good bet though. It should cost less than a dollar from Dick Smith. You will need two of them - one for each tail light.

    Maybe try a 10 Ohm resistor first. If it works that means less power drain from the car battery, and less heat being generated in the wiring harness and the 10 Ohm resistor, which is always 'healthy'. ( Power rating for the 10ohm resistor would be about 12V/10Ohm x 12v = 14.4 W i.e. say 15W ).

    Make sure you do a good vibration proof, wear proof insulation job on the two soldered ends of the resistor, since you are setting up a potential short cicuit if the insulation rubs through or falls off. Depending if there is any bare metal nearby, which there could be. There should be a fuse in the fuse box for this circuit, but always good to insulate joins properly, just in case.
    Last edited: Aug 8, 2010
  11. Davidman

    Davidman 4x4 Earth Contributer

    Thanks Millsy, so, the 10 (or 5) ohm resistor would go in the single wire that provides power to the indicator (In my case it is the yellow one). There are currently 4 wires, one earth, one for stop, one for tail and one for indicators.

    Sorry if it sounds a stupid question, but I am not an auto elec, no problems wiring new lights, LED's, stereos, UHF's etc in, just want to make sure when comes to this 'technical' stuff.

    Another question, are these things (resistors) waterproof if soldered etc properly, just in case they get a bit wet (read drowned) in the odd river crossing, or would it be better to add the resistor into the wire somewhere other than near the rear lights ?

  12. millsy

    millsy 4x4 Earth Contributer

    No, that would be connecting it in series. You need it in parallel. So you need to make two T junctions; one end of the 10 (5) Ohm resistor soledered to the yellow wire, and the other end to the earth wire. (Theoretically you do not have to cut either the yellow wire or the earth wire. But in practice you will proabaly will need to cut them to make a good solid T connection with your soldering iron.)

    So the current is simultaneously travelling through the indicator circuit and also the 10 ohm reisistor 'next' to it, side by side - parallel to each other. Neither the 10 Ohm resistor nor the indicator LEDs are affected by the other. They don't know that each other is there, if you like. But the flasher unit does! Because now it is having to provide more current than if the 10 ohm resistor was not in the circuit. ( They get two different currents. The 10 Ohm resistor will get a greater current than the LEDs, with their large protective resistors that reduce their current. The current in each leg of the parallel circuit are completely independant of each other. )

    Whereas if you connected the 10 Ohm 'end to end', that is in series, with the indicator, then the total resistance of the circuit increases, and they both get less current than if the other was not there. So they can 'feel' the effect of the other. ( They will both get the same current, because what current passes through the 10 Ohms has to continue on through the LEDs. This current will be slightly less than what the LEDs would have got without the 10 Ohms in series with them. ) Hope all that makes sense.

    These resistors are pretty rugged. A bit of water should not hurt them. But that's why you need to really do some proper soldered joints, rather than just use those quick and nasty 'spike through' connectors. If you are worried about water and corrosion, maybe even seal the joints with some sort of glue. Maybe a bit of epoxy, like 5 minute araldite. Or 'roof and gutter' silicone sealer. There is something called shrink wrap you can buy from the auto shop. I have never used it myself, but maybe that's the go. I think you apply it, like tape, and then use a soldering iron/clothes iron to warm it up ( probably by just putting the iron close but not touching ) and it shrinks tight onto the wires to keep out any moisture.

    Let us know how it all worked. Good luck.
    Last edited: Aug 8, 2010
  13. wedgie34

    wedgie34 New Member

    Heat shrink is what you're after. Specifically, heat shrink with glue is the way to go... Most heat shrinks dont have the glue, so make sure you get the right one... Jaycar, etc should have it...
    Sleeve it on, then shrink it with a cig. lighter or heat gun or anything else you can get hot...
  14. Vegetoast

    Vegetoast Active Member

    This is great and all but if you bring the current value up to make the flasher unit work correctly then you still use the same power as before.

    My idea of LEDs are too save power. If your handy with a soldering iron you can get a digital flashing light kit from jaycar or Dick Smith and make it fit.

    I have replaced all my lights with LEDs except the indicators as they are not on enough to make me worry about it.

    Also if your getting LEDs from Hong Kong or China on Ebay you will find that they wont last long as there are resisted up for 12v and the car runs at 14.4 or more when running with a fully charged battery.

    Another thing about LEDs on you vehicle.
    You can be found DEFECTIVE if you are questioned about them, they must display "Complies with ADR" with a buch of numbers somewhere on the LED unit.

    Hope this has been helpful;)
  15. Davidman

    Davidman 4x4 Earth Contributer

    LED indicator update.

    I tried a 10 Ohm resistor soldered into the system in the method described (hopefully got it right). This did not fix the 'fast flashing' so I removed the 10 Ohm and replaced it with a 5 Ohm. Unfortunately, still no good.

    I have attached some pictures of what I did, please let me know if it is right. Please note that I created a short section to include in the indicator wire. It was easier to make it on the workbench this way than try stuffing around under the rear of the car.

    (Don't pay too much attention to the soldering, it was only a quick solder to see if it worked)

    Any further advice would be appreciated.




  16. Big Matt

    Big Matt New Member

    If your going to heat shrink them dont tight arse on it, get some IP65 (i think) rated shrink. Its not cheap but its Quality rated to be water proof. We use it on bin cleaners thet we build and as yet we havnt had any problems with wet electrics

    PM me if you need a supplier (i dont have any left sorry)
  17. Davidman

    Davidman 4x4 Earth Contributer

    No point heat shrinking them, it didn't work.
  18. mudtiera

    mudtiera Member

    It wouldn't work because electritcy is like water takes the path of less resisence, so u need to put the resistor inline. Because ATM the current is just flowing past and having no effect.
  19. Vegetoast

    Vegetoast Active Member

    it needs a load to bring the current up and thats just throwing power away for the glam.
    my 2cents: your wasting your time.

    spend the big bucks on some ADR approved LEDs and it will work first go.

    go ask an auto electrician.
  20. millsy

    millsy 4x4 Earth Contributer

    Oops! Sorry I did not look at this earlier tonight. You have short cicuited the resistor with that wire running along its side! Would have been OK without that wire. What you have made is two paths for the electric current - one path through the resistance, and another just straight along the wire. But all the current, or just about all, will go along the wire, and its as if you have not even connected the resistor into your circuit at all. The flasher unit will not even 'see' it!

    Its a bit like going up a steep hill in your fourby. You can either go up the tough climb, or go up the easy chicken track right next to it. So about 99.9% of the current will just shoot up the side wire, and your flasher unit will hate you because this side wire is called a short circuit! A short circuit being a piece of wire, or metal that allows the electric current to go directly form the positive power side of the circuit (in this case the indicator yellow wire) directly to the negative power side (the earth wire in your wiring loom),without any resistance. So the current will be very large.

    Unfortunately the large current can cause damage if there is no fuse to blow and stop the current quickly. Hopefully this is what has happened in your case, and your indicater 'can' is still OK.

    So if you just cut out the middle 10mm of the piece of wire going along the side of the resistor you will have it right. And as I said, connect it back up to the earth wire and the yellow wire, try it out. If the indicators don't work you will need to find the fuse for the indicator circuit in your fuse box and check to see if it has blown.

    If the fuse has blown, just replace it with the same AMP rated fuse.

    If you reckon the fuse is still OK, because you can see that the metal strip has not melted, and appears to be still in tact, then maybe you have damaged the flasher unit and will need to buy another one. They are not too expensive. Should be around $12 to $15 I think. Its been a few years since I bought one.

    Hopefully no damage to the 'can' and it will work this time. I would go back to the 10 Ohm again, rather than the 5 Ohm. Good luck.
    Last edited: Aug 10, 2010

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