Author Topic: Indicator relay (Read 5362 times)

bigbadmad · « **on:** October 18, 2006, 06:30:25 AM »

Hi I've just registered but I've been reading this forum for a long time. I have a 1989 B4. The (naff) mini indicators that a previous owner fitted have fallen apart over the last year and I noticed a special offer on LED indicators - 4 LED indicators and a indicator relay for about £30. When I fitted the indicators and switch the indicators to left or right ALL the indicators come on. Great, I have hazard lights but no one knows which way I'm turning!
If I switch one of the LED units for a normal bulb unit they all function normally. My conclusion is that the LED units do provide enough resistance for the system to work properly. My question is has anyone else had this problem and if it can be cured by adding a resistor, what rating resistor should I use?

magicGoose · « **Reply #1 on:** October 18, 2006, 10:49:50 AM »

Well, now you know why they were on special offer.

Sorry, I had to say that.
The typical problem with LED indicators is that they don't draw enough current to make the relay flash, sometimes even lower wattage incandescent lamps can cause this. Putting a resistor in series would compound the problem, not solve it.
When you say that all the indicators come on when you activate the switch, do they all burn steady or do they all flash? Typically if there is not enough current draw the lamps will burn steady and not flash at all.
You have replaced the entire signal bodies, and not just put LED lamps in the existing sockets, correct? If so, I would suggest checking the polarity of the connections to the signals, because unlike incandescent bulbs, it matters to LED signals which lead is positive and which is negative. A reversed connection could give a current path to maybe mess things up in some strange way.
Just a thought.
Steve

bigbadmad · « **Reply #2 on:** October 18, 2006, 10:55:27 AM »

Cheers Steve, they flash ok... just all of them at the same time. The new indicators replace the old ones entirely as does the new relay, so the only orginal bits in the circuit are the wires/idiot light/battery and so far as I can tell they're wired in the right way.

Last time I buy cheapies... who am I kidding I love a special offer

magicGoose · « **Reply #3 on:** October 18, 2006, 02:27:12 PM »

Quote from: bigbadmad

Last time I buy cheapies... who am I kidding I love a special offer

Yeah, I have the same problem.

I just had another thought, though. When you replaced the LED with the original and it worked, could it be that THAT LED signal was causing the problems? What if you try to replace one of the other LED signals with an original and see what happens?
One other possibility may be grounding. Do the originals ground to the frame somehow and the LEDs not, or vice-versa?

stormi · « **Reply #4 on:** October 19, 2006, 05:45:56 PM »

I saw something on a website once about a very similar behaviour. Look at some websites that sell these things. The problem I read about was that the lights flashed incredibly fast. There was some "device" that could be bought that would slow the flash down, by drawing some of the current, etc, that made them flash too fast because the LEDs don't draw enough.

I'm sorry, I can't recall where I read it. I do remember that the site I found it on sold the LEDs as a "safety" item. They also sold the ones that when you hit the brake they flash several times, then go solid, to get drivers' attention. (I do that manually, when I notice someone on my tail especially.)

400runner · « **Reply #5 on:** October 19, 2006, 08:30:16 PM »

If you have not figuered out this problem yet. than here is the fix. I had the same problem and it turns out that the original relay is a mechanical one that needs more current than the LED pull to make it work. So if you take the original relay and go to your nearest auto shop and buy an electronic relay which works by sending power to the turn signal rather than having the power drawn from. this will fix your LED turn signal issue. I hopw this makes sence. Make sure that the new relay will fit the bandit. Usually from cars in the late 70s and most 80s Good luck

bigbadmad · « **Reply #6 on:** October 29, 2006, 08:07:41 PM »

I was right, kinda. I ordered the resistors from the bottom of this page: http://www.toolparts.co.uk/acatalog/LED_Indicators.html
What I didn't get right was they needed to be wired into the circuit in parallel not series (why I cannot figure out).
I now have bright LED indicators that flash correctly and my winter bike is ready in the nick of time!

magicGoose · « **Reply #7 on:** October 31, 2006, 10:34:48 AM »

Glad to hear you got it sorted!
Flashers often have trouble with the tiny current draw of LED signals, but I wrongly assumed that since you bought them together, that they would work together. IMO, whoever sold you this kit needs a good slap upside the head.
regards,
Steve

Herr Tod · « **Reply #8 on:** October 31, 2006, 12:54:41 PM »

I use a digital relay, you can use LED and normal blinkers. Led only, normal only or some of both, doesn't matter, it will always blink at the same rate.

bigbadmad · « **Reply #9 on:** November 01, 2006, 10:22:37 AM »

Quote from: magicGoose

Glad to hear you got it sorted!
Flashers often have trouble with the tiny current draw of LED signals, but I wrongly assumed that since you bought them together, that they would work together. IMO, whoever sold you this kit needs a good slap upside the head.
regards,
Steve

Yeah, it is annoying that the relay sold with the set didn't do the job. In fact the relay is the weak point of the set in another way too: It has one of those annoying beeper relays that beeps to remind you that your indicators are on... I soon had that apart and unhooked the beeper I can tell you. :D

bigbadmad · « **Reply #10 on:** November 01, 2006, 10:23:18 AM »

Thanks to all who posted