22R88

I have installed some Sunpro gauges and was wondering where is the best place to splice for the gauges backliting. I want them to work with the dimmer rheostat so I can tone them down with my dash lights. Any tips appreciated.

22R88

xxxtreme22r

Why not wire them into the dimmer switch?

22R88

Well, that is what I tried to do. With the dimmer unpluged and the lower dash off I checked for voltage. On one side of the dimmer connector plug I have 12 or so volts with the headlight switch on. I figured that the other side of the plug would carry the variable voltage once I plug the dimmer back up, but I am seeing nothing at the wiring going to the gauge. maybe I didn't make a good connection. I wil recheck. Thanks for the reply.

22R88

4Crawler

iTrader: (3)

Generally the Toyota dimmer switch is on the ground side of the dash bulbs, while most after market gauges have the internal bulbs hard wired to the gauge housing that is grounded. So they are set up with a single wire for the bulb, while the Toyota dash lights have two wires, one for the bulb power and the other for the dimmer wire. So if you hook that gauge bulb to the dimmer wire, you'll have all the other dash lights in parallel feeding the one gauge bulb to ground with the dimmer in parallel with that same bulb. So the dimmer will dim the dash bulbs, but will make the gauge bulb work opposite, as the dimmer increases resistance, the gauge bulb will take more current and get brighter. So you either need to try and modify the gauge to isolate the bulb from the gauge housing/ground, or you can just hook the gauge light to a switched light power signal and if needed, add a series resistor to dim it down as needed.

22R88

Thanks for the reply, The gauge instructions alluded to what you said but I didn't quite understand what they meant. You clarified it greatly for me. Thanks
Could a wire in a small potientiometer from radio shack in line and dial down the voltage ? If so, what size would I need ? They show a 100K, 10K, and a 1K ? Its greek to me !!!!

22R88

crawler85

i just ran into this problem of having the aftermarket gauge light work opposite the dimmer switch.

please tell me there is a simple way to make the gauge lighting go with the dimmer.....

dumbest design ever for toyota?

4Crawler

iTrader: (3)

I think it is a dumb design on the part of the gauge mfg. If they would just provide two light terminals, you could wire the light up any way you wanted to. But since they usually tie the light bulb socket right to the case of the gauge that you need to ground, you end up having the back light hard wired to ground. So the easy fix is to not connect the back light power to the dimmer, instead hook it to the switched 12 volt power going to the gauge. If the light ends up too bright, install a resistor in-line to dim it down and then call it good. Otherwise, tear the gauge apart and see if it is possible to isolate either the light bulb or the gauge electronics from the case and then you can add a wire to leave a separate light and electronics ground. Or, if you can't do that, one could always wire up a power transistor or amplifier to take the dimmer voltage, buffer that and output a proportional signal to the bulb in the gauge.

crawler85

apparently the 2nd gen tacomas are the same but they have a green/ green-white wire they can connect to.

http://www.toyotanation.com/forum/61...ht-wiring.html

do you know of any such wire in our 1st gen 4runner/ 2nd gen trucks?

Spookee

Its being a while but i think i used the cigarette liter positive wire.

4Crawler

iTrader: (3)

Not aware of any such wire, at least per the wiring diagram, although there may be one. You have all the dimmable lights hooked together on the positive side then all the grounds tie together and run to the dimmer (rheostat) and then to ground. So all those bulbs have essentially 12v on the + side and then between 0v and 12v on the ground side (with 0v you would have maximum current/brightness and with 12v on both sides of the bulbs, you get 0 current and no light). So if you look at all the Toyota back lights, all those bulbs have two wires connected to them, so they are not hard grounded.

But you can hook to something like the lighter wire or parking light positive wire or similar if you want the switched power connection. As long as you grab some power that turns on and off with the key that will work fine. I used the parking light + wire for my gauge lights, that way the back lights turn on and off with the parking lights, but there is no reason any switched power wire wouldn't work. Who cares if your gauge light is on during the day, you can't tall unless you drive into a dark parking garage or something.

Co_94_PU

iTrader: (-1)

The stereo harness has the proper signal, +0-12v corresponding with the dimmer knob, it's label "J"



IIRC The clock, upper right hand position. Has the same +0-12volt

If you want to put an inline dimmer/POT, you could add a salvaged dimmer.

The toyota dimmer is 0-5, or 0-10 ohms depending on type. and Has A BIG power rating.

If you source something other than the toyota one (eg. radio shack) you need to make sure it's power rating is high enough so it doesn't melt.

Here is a calculator and some background information. http://www.bcae1.com/ohmslaw.htm

To add an array of resistors you'll want to stay above 1kohm or you'll need larger than 1/4 watt resistors

crawler85

4crawler,

at what location did you tap into the parking light? do you remember the color? thanks.
................................

co 94 pu,

i looked for the dimmer wire at the radio, and it is currently a nightmare....

i have 2 live wires with the ignition off routed to the radio (removed). my cigarette lighter is always live too, so i have to find where the previous owner decided to "jumper" my "ignition on" power wire to keep it live without the ignition on.

on top of that i could not locate the dimmer wire.

4Crawler

iTrader: (3)

My OEM radio connector was long gone when I bought the truck, all those wires are cut and wrapped with tape. I rewired my lighter socket to be always on as well, just ran a fused wire back to the battery.

But for the parking light wire, I went up to the front where the parking lights are and tested voltages on them and picked the wire that went to 12 volts when the lights were on, so whatever color wire is not the ground wire, might have been green, but I last worked on that 15 years ago. Just figured that was a handy wire to have so I ran it up to a little terminal strip I installed in the cab:
- http://www.4crawler.com/4x4/CheapTri...rnSignal.shtml

Co_94_PU

iTrader: (-1)

Check for the clock connector even if you don't have a clock it might be there pluged into the cover for the hole.

You guys can have the +V extra dimmer controlled wire in my stereo harness Think it's for the cd player but my factory changer (from a corolla) doesn't have a plug for it.

4Crawler

iTrader: (3)

At least the wire on the clock is basically on bright/dim signal, it is basically from the tail light relay. So it is either 0v or 12v but nothing in between. You'll note if you have the clock display on (bright) and then turn on the headlights it goes dim, but change the dimmer control and the clock stays the same intensity.

That wire for sure would work to power the gauge lights but if you want them dimmer you need to stick a series resistor in-line. I'll guess the radio connector wire is similar. Seems most aftermarket radios are using that type of signal now instead of an analog voltage just a bright/dim signal.