Mixing LED and incandescent indicators

piranha-bro2

piranha-bro2

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Melbourne
Anyone know if a non load-sensitive indicator relay (such as the Tridon LED04) works properly if you have 21W incandescent front and LED rear indicators? I'm hoping that the relay works regardless of load, therefore should be no probs.

Thanks,
Quentin
 
If "non load sensitive" means what it says, then there shouldn't be a problem.
About a year ago I bought an indicator relay on line that was advertised as non load sensitive. But when I got it, it was just a standard bi-metallic type, totally sensitive to load. Not happy.
 
That would piss me off big time as well. I reckon the Tridon is a top brand so will probably see if Repco have them cheaper than Supacheap ($51) - sen them online for $40 but then there's shipping.
 
One thing PB2, the LED04 is the one to use if you have TWO idiot lights (for left and right), is that the case?
Otherwise use the LED03 if there’s just one (y)
 
The LED03 is 3-pin but the relays I've always used are two pin. Is there a reason the LED04 (I've bought two!) won't work with one idiot light? The idiot light just works by earthing through the opposite side (so one of the wires to the imbecile light comes from/goes to the left and the other comes from/goes to the right. Does that stuff up the operation of the relay?
 
If you’ve got a separate left and right dash light then use the LED4, if you try to connect one dash light to both left and right you’ll bridge the relay and have all 4 indicators on at once. At least that’s what I think 🤔 from looking at the diagrams, I haven’t tried it 😉. I have used the LED3 on mine because I’ve got just one dash light 👍
Never mind about what you’ve used in the past because the LED relays use different tech so they aren’t current dependent 😁
 
piranha-bro2 said:
The LED03 is 3-pin but the relays I've always used are two pin. Is there a reason the LED04 (I've bought two!) won't work with one idiot light? The idiot light just works by earthing through the opposite side (so one of the wires to the imbecile light comes from/goes to the left and the other comes from/goes to the right. Does that stuff up the operation of the relay?
Click to expand...

The idiot light simply connects between the left and right indicator circuits in the original system. When one side is powered up, the lamp "earths" through the other side. The current is bugger all so not enough to light the filaments in the indicators of the "off" side.

However, LEDs only allow current to flow one way (the clue is the D in their name :) ) so the earth current has no path to ground. You'll need to buy a couple of diodes and wire the idiot light as shown below.
 

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But I do like the simplicity of one idiot light - are these diode things just a wire in-wire out affair, and can I buy them from a place like Jaycar? Are they a specific size, number, blah blah?

Thanks for the info guys!!
 
Yep Jaycar'll do. Something like THIS or just ask the spotty youth at the counter. You can just put the legs into a strip connector, pieceofpiss, or use crimps or whatever.
On the other hand... I can't stop myself from asking... why not use the LED03 which already has the extra guff inside..? I guess it depends on what wiring you've got already, if you need to run an extra wire or whatever I could understand it, otherwise it seems like an extra complication that the next person (maybe you!) will look at in a few years and wonder what the hell is going on...
 
Yes, diodes are just one wire in and one out, but they're polarity sensitive so you have to get them the right way around. That's the whole point of them. They only allow current flow one way. You need them in that circuit to stop one side of the indicator circuit feeding back through the other side, otherwise all the indicators would light up together. Diodes have a band around one end to indicate the polarity. Current flows from the non-banded end towards the banded end. In other words, connect the non-banded end to the positive feed and the banded end to the globe.

They're available from Jaycar. Ask for 1 Amp rectifier diodes or quote part number 1N4004. They have them in packs of 4 for 98 cents. They'll probably sell them individually if you can't afford to stump up the 98c for a pack :)

I dunno whether you're using an original wiring harness. If so, doing the wiring modification would be dead simple because you already have the left and right feed wires going to the idiot light. All you need to do is disconnect them from the lamp holder, solder a diode to the end of each wire (insulate the joint with a bit of heat-shrink tube or tape), then connect the other end of those diodes together and wire them to the centre terminal of the globe holder. Earth the globe holder itself and that's it.

If you go with separate idiot lights for left and right, you obviously don't need diodes because they're independent circuits.


PS: Andy beat me to it, but he's gone for a 3A diode. Makes no difference as the idiot light only draws about 0.25A and the diode prices are about the same. I haven't figured out the "someone else has already responded" warning yet.
 
Had already ordered the LED04 ... they just arrived too! Total rewire for the SFQ - streamlining everything I can. Either option (diodes or two idiot lights) are dead easy, so I'll toss a coin. Jaycar isn't too far from me, so reckon I'll try a bit of electrotrickery - always marvelled at people who could put transistors and stuff together to make things o_O
 
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