One thing that has not been suggested yet is putting the multimeter into the AC VOLTS setting. That will quickly reveal any PWM signal, no matter the frequency or duty cycle..
AND, dependent on where the new LED lights came from, it might be possible to contact either the distributor or the manufacturer to learn the reason for the unique operation.
It might also be that the new lights are intended to satisfy some goofy safety rules demanding illumination at a lower level at all times. Some states and some countries do have really goofy rules, intended to somehow provide more safety.

 

I am still not convinced that you have characterized what is happening correctly. A device that is given 10V when off and 12V when on is extremely odd. Something I have never come across before.

And how did you determine it is not PWM?

 

It's not PWM, I put a scope on it, and this is the way the EV can bus work. I'm not thrilled and wasn't even expecting it but it is how this can bus is setup.

I'm not opposed to wiring it myself but I still need a trigger if I use a mechanical relay and the constant 10v becomes an issue.

 

OK, NOW PWM, so forget the SCR scheme.
So perhaps a steady dim as in the parking lights function, with the much brighter light for stop light and turn signal functions would be OK. That would be the easy out.

 

Yes, it sounds like the lights are intended to be lit brightly when signaling or braking (12V) and less brightly otherwise (10V).

And your light does not respond well to that, so it is not an appropriate replacement.

 

Yes, it sounds like the lights are intended to be lit brightly when signaling or braking (12V) and less brightly otherwise (10V).

And your light does not respond well to that, so it is not an appropriate replacement.

Negative, the 10V constant is not intended to be a dim option. As i keep repeating it is part of this systems Can Bus and how it operates. Accept the facts and stop trying to come up with justification for your reasonsing to disprove the obvious.

The goal is to provide a solution. I'm at a point I've already come up with my own solution which is what I was initialy going to execute before I came here. Seems like some of you are more concerned about disproving the facts than just providing a solution based on the facts. If you don't have a solution thats fine. It is becoming futile having a conversation about this now.

To those who helped and provided suggestions, thank you for your ideas.

 

The CAN bus is a signaling system using a differential pair. It does not power devices, it controls them. So no, 10V for off and 12V for on is not part of the CAN bus. If you can show me a spec that says it does, I will admit I am wrong.

 

OK, so here is another idea that I have not suggested before. But it will need a true common reference. when the voltage across is ten volts the series transistor in the ground side is not switched on, but when twelve volts are present then the light negative is tied to common because the transistor switches on, completing the return side connection.

 

OK, so here is another idea that I have not suggested before. But it will need a true common reference. when the voltage across is ten volts the series transistor in the ground side is not switched on, but when twelve volts are present then the light negative is tied to common because the transistor switches on, completing the return side connection.

Sounds vaguely familiar.

 

Sounds vaguely familiar.

Indeed it may have been posted, and ignored, already.