LS430 Instrument Panel Swap

[JZH]

I'm using almost everything from a 2004-06 LS430 in my swap, including (I hope) the instrument panel. I've got the All4Swap MPX-GATE 1M interface module for certain functions, but I'm not yet sure how I'm going to integrate the instrument panel dimming feature into my vehicle.

The LS430 controls the brightness of the instrument panel LEDs, as well as the incandescent light bulbs in the car's switches and indicators, using a simple rheostat connected to the Driver Side Junction Box ECU. I'd prefer not to have to use all that...

From the wiring diagram it looks like there must be a PWM controller built into either the D-S J/B ECU or the Combination Meter, because the panel uses LEDs, which usually don't work properly on the same dimmer circuit as regular light bulbs. There is one pin on the panel which is labelled "ILL-" in the wiring diagram, which I believe is the label Toyota usually uses for the modulated side of a PWM-controlled dimmer circuit. I'm guessing the other side of the LEDs would be fed 12v from the IGN circuit, which also feeds into the panel.

Anyone know how to control the brightness of the panel?

Cheers,

JZH

 

[ivan129]

Some LED dimmers use a switching (PWM) gnd, wired to the cathode (-ve) side of the LEDs. All the anodes are commoned to +12V. If you Google you will find plenty of 12V LED dimmers if you can get yours to work.

 

[JZH]

Thanks, I plan to use a PWM-type dimmer from a Toyota, e.g., 84119-60100 (2002-09 Landcruiser wOptitron). I was wondering if anyone knew for sure how the LS430 panel is wired internally.

JZH

 

[JZH]

I've now got an LS430 instrument panel to test, and it's now looking like the PWM circuit is in the D-S J/B ECU (which I don't have), because connecting the output of the LS430 dash panel rheostat to the ILL- pin of the panel doesn't really dim anything. (It jumps down to about 80% when I turn the rheostat--same as when I put 12v on it.)

I'll try it with an actual PWM dimmer for LEDs and see if I can get the panel to dim properly. (Still not sure the Landcruiser dimmer is actually a PWM dimmer, though. Further investigation required!)

JZH