LED Interior Lights, can it happen?

I have been trying to upgrade the interior bulbs on my 97 to brighter LEDs. After replacing all the bulbs the interior is much brighter with the LEDs, however when the lights dim off the LEDs flicker like strobe lights throughout the car. I have tried various different brands of LED bulbs with no success. I have done the same upgrade on my Lexus with the same dim off feature without issue. Has anyone been able to find a bulb that works or does the Riv dimming system only work with incandescent bulbs?

urbanski_m wrote:

I have been trying to upgrade the interior bulbs on my 97 to brighter LEDs.  After replacing all the bulbs the interior is much brighter with the LEDs, however when the lights dim off the LEDs flicker like strobe lights throughout the car.  I have tried various different brands of LED bulbs with no success.  I have done the same upgrade on my Lexus with the same dim off feature without issue.  Has anyone been able to find a bulb that works or does the Riv dimming system only work with incandescent bulbs?

the Riviera auto-dimming assumes incandescent bulbs, and dims them by pulsing them on and off via the Multifunction Alarm, Lock and Lighting (MALL) computer. Since an incandescent bulb turns on gradually (compared to an LED) a very short full on interval (fraction of a second) repeated several times a second gets you a dim orange glow.

The only way to change that would be to change the pulse intervals in the MALL. I imagine that could be done, but I do not know how. Pulsing for LED dimming would be a different pulseform than for incandescent dimming.

What you could do is convert the pulses to a voltage in proportion, then use that voltage to light some number of LEDs in an array. LED indicator bars are sold that already light a number of segments depending on applied voltage to the terminals. Here are methods for the pulse-to-voltage conversion: https://electronics.stackexchange.com/questions/64360/circuit-that-can-convert-current-pulses-to-voltage.

Alternatively, if the Lexus lighting controller is a separate computer module perhaps it could be wired into the Riv to control the lighting? I don't know for sure.

Thanks albertj, that answers my question and then some. Looks like I am going to stick with the incandescent bulbs.

urbanski_m wrote:

Thanks albertj, that answers my question and then some.  Looks like I am going to stick with the incandescent bulbs.  

That's what I did, except a couple things.

I did put LEDs in the CHMSL and the inboard stoplights. I did not have to install resistors, the incandescents I left in work fine for that purpose, I have no fast-flash problems.

I tried LEDs in the sidemarker lights, they dimmed due to exposure (the LED elements went out one by one over teh course of several months -- I put halogens in instead (got them off Amazon or eBay - https://www.amazon.com/Partsam-Miniature-Halogen-Marker-Camper/dp/B016W26YA4 for example). Turns out many if not most name brand auto mini bulbs are halogens by the way.

Thanks for the info. I did put LEDs in the front side markers lights years ago and have had no issue. I might swap out the CHMSL and the cornering lights with LEDs