LED warning light. (2015)

Diver3284 · Jun 24, 2015

I was fooling around with some small T5 wedge LED's and decided to see if I could replace the turn signal warning light in my headlight shell. I have a standard (pattern) 12 volt lucas set up on my '74 Roadster. I guess the LEDs are single polarity because it only worked when one side indicator was flashing, and if I reversed the connection it worked with the other side.

I am an electrical idiot so my questions are: 1] would a dual polarity T5 work, if there is such a thing?
2] is there another gizmo that will fix the problem without costing an arm & a leg?

Anonymous · Jun 24, 2015

Did you wire the diode between the flasher can and the indicator switch?
Ta.

L.A.B. · Jun 24, 2015

Diver3284 said:
2] is there another gizmo that will fix the problem without costing an arm & a leg?

Two diodes and the LED connected according to beljum's drawing in the link:
led-indicators-t14612-15.html#p176199

manxman · Jun 24, 2015

needing said:
Did you wire the diode between the flasher can and the indicator switch?
Ta.

Don't think an LED will work in series with the flasher and lights. LED's are very low current. They usually need a resistance load to limit the current to a few milliamps.

Manxman

manxman · Jun 24, 2015

Diver3284 said:
I was fooling around with some small T5 wedge LED's and decided to see if I could replace the turn signal warning light in my headlight shell. I have a standard (pattern) 12 volt lucas set up on my '74 Roadster. I guess the LEDs are single polarity because it only worked when one side indicator was flashing, and if I reversed the connection it worked with the other side.

I am an electrical idiot so my questions are: 1] would a dual polarity T5 work, if there is such a thing?
2] is there another gizmo that will fix the problem without costing an arm & a leg?

An LED is a light emiting DIODE. A DIODE is a solid state device that only allows current o flow in one direction. Like a one-way valve. It just happens to emit ligh while current is flowing through it.

The indicator light needs current to flow in either direction, depending on which indicator is used. This is because it is grounded through the unused light. Sounds weird, but it works.

if you insist on using a LED, you will need 2 of them wired in parallel. An alternative is to put in a relay, powered off the flasher can, driving a single LED. But that would be a bit silly. I would leave it as is.

Manxman

MikeG · Jun 24, 2015

Install your LED lamp in the shell and ground the negative side of it. Take the two wires coming from each indicator lamp and install a diode in each so power can only flow in one direction through the wire. Pay attention to direction of current flow through diode! Connect both wires to the positive side of the LED indicator and it will work fine. The in line diodes keep current from one lamp backfeeding the other and turning on all four blinkers at once. I'm assuming you have a negative ground LED as thats most common, it will not matter if the bike is still positive ground or not.

Mike In Mass · May 16, 2019

"Install your LED lamp in the shell and ground the negative side of it. Take the two wires coming from each indicator lamp and install a diode in each so power can only flow in one direction through the wire. Pay attention to direction of current flow through diode! Connect both wires to the positive side of the LED indicator and it will work fine. The in line diodes keep current from one lamp backfeeding the other and turning on all four blinkers at once. I'm assuming you have a negative ground LED as thats most common, it will not matter if the bike is still positive ground or not."
What value diodes would be used in this set-up? Thanks !

ntst8 · May 17, 2019

Paul Goff sells a "tweaker" which does this. Scroll down in the link below.
http://www.norbsa02.freeuk.com/GoffyLEDIndicators.htm

Alternatively I made my own, the spec called for was N4001 but all i could find was N4004 (which has a higher rating). They cost next to nothing at an electronics shop, i had to buy a pack of four.

Mike In Mass · May 17, 2019

Many thanks Lain !

HRD · May 17, 2019

ntst8 said:
Paul Goff sells a "tweaker" which does this. Scroll down in the link below.
http://www.norbsa02.freeuk.com/GoffyLEDIndicators.htm

Alternatively I made my own, the spec called for was N4001 but all i could find was N4004 (which has a higher rating). They cost next to nothing at an electronics shop, i had to buy a pack of four.

Think you need 1N4001 or 1N4004 .

ntst8 · May 18, 2019

HRD said:
Think you need 1N4001 or 1N4004 .

Sorry, my bad, I copied it incorrectly from my own thread elsewhere on here

.

Tornado · May 21, 2019

FYI: there are non-polar type LEDS made for warning lights in various sizes:

https://www.superbrightleds.com/mor...-bulb-4-led-miniature-wedge-retrofit-car/198/

Pretty cheap too.

LED warning light. (2015)

Diver3284

Anonymous

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L.A.B.

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manxman

manxman

MikeG

Mike In Mass

ntst8

Mike In Mass

HRD

ntst8

Tornado

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