Led light turn on at specific Voltage

[djmixalot]

Hi,

Setup is very simple, updating led lights on a vehicle, the older 3" round led lights have been replaced with new ones.

This vehicle put out a constant ~10.2v on the lights wiring. (turn signals, brake lights, 3rd brake light) when the ECU drives the circuit to ground the voltage goes from ~10v to 12V and the lights light up accordingly.

The older lights, lets use turn signals as an example, would turn on when you activate the turn signals. When the turns signals were off they remain off despite the 10v.

These new round led lights have about a dozen led in this 3" round light. Due to the fact there is ~10v on the turn signal wiring, it lights up about 4 of the 12 led at all times. When you actually activate the turn signal, it turns on the other 8 led on and off as expected but these 4 remain on all the time.

The goal is to make the new lights work like the old lights. So a modification is needed for each of these lights. I'm looking for a clean solution since this needs to be done on each of the lights.

1. Running resistors in serious dimmed the 4 led which were on all the time but than none of the lights work when the turn signal is turned on.

2. Added a pair of diodes schottky but it made no difference.

Was thinking a comparator would be ideal however its all IC mounted and not ideal. I'm thinking maybe Zener diode would be the best option.

Thoughts?

 

[Diver300]

Can you clarify my understanding of the problem.
This is my undestanding at the moment after carfully re reading the thread.

1 - You have replaced the existing rear LED light clusters on the vehicle with different LED rear light clusters.
Four of the LEDs in these clusters remain on all of the time. This did not cause a problem with the caravan brakes.
(I originally thought this was when the brake problem started.)

2 - With the original plug in filiment bulbs on the caravan there was no problem with the electric caravan brake coming on when the side lights were turned on.

3 - You replaced only the stop and tail light filiment bulbs (5 / 21 watt) (NOT the turn signal bulbs. ) in the caravan with LED bulbs. This is when the problem with the caravan brakes coming on when only the tail lights were on switched on.

Les

There are two separate issues in this thread.

A) The OP, djmixalot from the USA, had the original problem with changing one type of LED lamp for another on an EV, on the EV itself. He didn't answer many questions directly and has now gone away.

B) Tex260Z from Australia, had a problem with the caravan brakes come on when he changed the 21/5W caravan bulbs for LED replacements. Tex260Z has answered questions, even though he reverted to the filament bulbs.

In your post, item 1 is about problem A, but in problem A there is no mention of a trailer.

Item 2 and 3 are about problem B

 

[Les Jones]

Thanks Diver300 for pointing out that that Tex260Z posted his problem on sommone elses thread rather than starting his own thread. I had not noticed that.

Les.

 

[Diver300]

Thanks Diver300 for pointing out that that Tex260Z posted his problem on sommone elses thread rather than starting his own thread. I had not noticed that.

Les.

It was partly my fault that there was so much about the caravan brakes. Tex260Z posted his problem as a comment (post #24) and I asked him more questions about it.

 

[Tex260Z]

Can you clarify my understanding of the problem.
This is my undestanding at the moment after carfully re reading the thread.

1 - You have replaced the existing rear LED light clusters on the vehicle with different LED rear light clusters.
Four of the LEDs in these clusters remain on all of the time. This did not cause a problem with the caravan brakes.
(I originally thought this was when the brake problem started.)

2 - With the original plug in filiment bulbs on the caravan there was no problem with the electric caravan brake coming on when the side lights were turned on.

3 - You replaced only the stop and tail light filiment bulbs (5 / 21 watt) (NOT the turn signal bulbs. ) in the caravan with LED bulbs. This is when the problem with the caravan brakes coming on when only the tail lights were on switched on.

Les.

1. incorrect, I replaced the standard filament Stop & Tail lamps with LED Stop & Tail lamps.
2. Correct.
3. Correct.