Interior light dimmer switch swap

Hey there
anyone know if a different toyota dimmer switch would work in the 2nd gen tacoma to allow for turning on the dome light from the switch?
if so, what model switch would fit?
would the switch from the matrix/vibe work in this truck? it looks to be the only toyota dimmer switch to have this feature

i would like to have this option if possible- i have additional modifications in mind that this would be the first step

thanks

 

I'd need to see the wiring schematic for the Matrix, but the switch probably just has an extra set of contacts to ground the dome light. I doubt it will just plug in, and you'll need to add some wiring, but should be doable if it fits into the dash cutout.

The only thing I question, and maybe someone else here will see this and comment: the factory dome light has three options selected by the switch on the dome light itself: on, off, door. Power is supplied to the light all the time. With the on option, all you are doing is grounding the light to the body near the light itself. Then there is off, and the door option. The door option grounds through the body computer. That's why the light fades on and off, instead of being instant. I don't know what effect it would have on the computer if you grounded or disconnected that wire. You don't want to fry it. I don't see that happening, but I don't know that much about the actual computer. I can tell you that the wire involved is very small gauge (20?) and I wouldn't want to add any additional load to it. I did try and tap a relay coil onto that wire on mine, and while I did not damage anything, it did not work right. The relay's coil chattered when the factory light was fading on and off.

 

Ya, wouldn't be a plug in option.
The dome light has 3 wires going to it.... Hot 24/7, ground (might just be the chassis and not a wire), and the signal wire from the control relay, which is triggered from a circuit driven by the door pin switches... not directly by the pins.

You could theoretically tap into the door's pin switch and wire that to the dash on a separate switch.
I don't know if there is an alternative dimmer available that would handle that function.

 

I would expect that because the relay is designed for a constant voltage... the computer is ramping the current.

It shouldn't be too difficult to come up with a circuit that could "read" the signal and trigger a relay with that... you just need to filter it and regulate it to hold a steady level until a cap discharges then it dumps.

But the OP is wanting to go the other way.
You could theoretically ground directly to the wire from the light... and to protect the computer, just put a diode in series with the computer.
Perhaps a safer way to go would be to trigger at the door switch, but that's not going to provide an instant-on/off... it's going to fade off.
Not too good when you just want to hit it so your passenger can read a map or fish something out of her purse.


This circuit will turn the light on without impacting the computer and drawing no additional current through it.

 

Your diagram looks like it would work for what the OP is trying to do.

In my case I was trying to make the added lights in my camper shell come on with the factory dome light when unlocking the doors using my factory keyless system. The wire involved is so small I was afraid to add any load to it.

 

Agreed for your application.

You do need to drive a relay, and to trigger it with something with a hard cutoff rather than allowing the computer to ramp the level down.

 

so basically i want to have 2 led's come on in a modified 3rd brake light when the doors unlock, like the post above but also to control it with the switch- wouldnt' the switch from the matrix (which looks like it should fit) essentially trick the computer into seeing a door pin open? or would this create a whole other host of issues? your input on this is really appreaciated

 

In theory, you could trigger from the door pin switches, or from the diagram I posted, but I don't know how the Matrix switch is wired. It may or may not have a simple make-break contact.

If you convert the interior light to LED, that'll knock your current draw and adding two more similarly-sized LEDs as bed lights would not be a problem.
Check the size of the fuse to get an idea of the available current, derate to 80%, so if the circuit has a 5a fuse, you can pull 4a from the circuit.
4a at 12v is about 48 watts total for the 3 lamps.