Instrument cluster LED dimmer instructions (M/T 2/3RZ) $7

(Note: See RysiuM's post for alternative: https://www.tacomaworld.com/posts/17724575 )

Step 1: Buy something like this: https://www.ebay.com/itm/0-10V-Dimm...ller-DC5-24V-for-LED-Light-Strip/252476201661
A $7 LED dimmer from China. This one is a low-side switch, which is preferred because to switch on the high-side would require tearing up a bunch of wiring.


Step 2: Find a 50k pot. Solder an 18kΩ resistor between the left and center terminals and one end of a 4.3kΩ resistor to the right terminal. Then attach three wires to the left, center, and free end of 4.3kΩ resistor. Like this: The resistors aren't strictly necessary, but the results are much better with them. The above dimmer has an effective 26kΩ pull-up on the control line and only works 0-10v. Those two resistors make the whole span of the pot change the brightness usefully. We can't use the rheostat because 1) it's only 10Ω, so would burn a ton of current if we tried to use it like this and 2) unlike a pot, a rheostat makes a non-linear voltage-divider.

3) Take the pot, two more wires with blades crimped on, and a fuse tap and screw into the dimmer as follows:
Pot left → 0-10v V- (Ground)
Pot center → 0-10v V+ (Control voltage)
Pot right/resistor → Load V+ (+12)
Fuse tap → Power V+ (+12)
Wire 1 → Load V- (PWM)
Wire 2 → Power V- (Ground)
Like this:

Note that the pair of wires labelled (Ground) above and the pair labelled (+12) are each
interchangeable. We're only using, the misleadingly labelled, 0-10v V- and Load V+ to save a couple of splices.

4) Now stuff it under the dash somewhere. Remove the rheostat and screw the pot on in its place (a washer might be useful. There's also a metal tab that sticks up on my pots that you'll want to snip off). Plug wire 1 into the rheostat socket with a green and white wire and plug wire 2 into the rheostat socket with a black and white wire. Plug the fuse tap in somewhere. and that's it, you're done!


It is actually functioning in the above picture. The pot runs from very nearly 0 volts to 9 and half or so, turning the LEDs from off to really fucking bright. Don't put it there though, I took the above photo before realizing the vent duct won't fit.

Caveat: I don't think there are any fuses in that panel that one can tap that will keep the dash lights on when the car is off but the lights are on. This doesn't bother me at all, but if it bother's you you'll want to find the lights circuit to tap off.

 

Here's what the pot looks like installed. You might want to grind it into a square, though I just jammed the Toyota knob on as is.

 

Is this just for dimming the leds in your cluster? The ones I put in my 03 sim with the stock dinner just fine

 

Yeah. The LEDs I have dimmed a little, but nothing like they're supposed to. Definitely didn't turn off. Not many may care, but now they transition from bright to off nice and smoothly through the whole twist.

 

Or you can go lazy way and get electronic dimmer from 1st gen Tacoma or 3rd gen 4Runner

https://www.tacomaworld.com/threads/dimming-led-dash-lights.546723/#post-17724575

https://www.youtube.com/watch?v=RlmLWaBk4QA

 

Shit! coulda told me sooner.
So that's what that A/T nonsense meant in the FSM wiring diagram...
Is that actually a PWM dimmer or just a voltage divider?

 

Mine do dim the whole way to off. Maybe I bought dimmable leds or something...who knows

 

It looks like 2000 Tacoma with Automatic transmission (note A/T on EWD) and with 5VZ–FE with Manual transmission (note *3 on EWD) are equipped with electronic (3 wire) dimmer. 2.7 and 2.4 Tacoma with Manual transmission (note M/T on EWD) is equipped with rheostat. This is why some people report no problem with dimming LED in dash - they have Tacoma already equipped with electronic dimmer from factory.



Yes, it takes some time to get understanding all the options and variants depicted on EWD, at there always more wires and connections shown on EWD than there are on particular truck.

Oh, and the electronic dimmer if it is PWM, it is well smoothed out (no flickering). It might be just variable voltage regulator.

 

I have updated the title and the post to reflect this new information. Thanks.

 

I bet you have an automatic and/or V6. RysiuM has solved the mystery of why cluster LEDs dim for some but not others.