Wiring Identification

Got lucky and found these behind the only blank I had. I tested the light green wire and out of all 3, light green, and green/white, and green, it was the 12V "on" wire with the key. Perfect for tapping into for my otrattw switch led indicator light. Now I need to figure out which one is the dimmer/ground and main ground so I can tap into the dimmer/gnd option so my switch led will operate as all my other switches and dash lights.

My question is does anyone know what the other wires might be? How can I test the ground or dimmer/ground with a voltmeter?

 

cant you just put the dimmer to the lowest setting and see which wire is drawing less wats? Im sure the red wire is for diff lock? if you had one?

 

The top 2 (or the 2 to the right in your picture) will be the dimmer ground and illumination power. I can't remember which is which but a test light will tell you which is power and which is ground.

 

Yea the only one reading anything is the light green wire. The other 3 are showing nothing on the voltmeter (assuming I'm using the proper settings on the meter)

 

Tks Pugga, for some reason those two aren't showing a reading at all when I use the meter. (dont have a test light)

The 3rd from the right in the pic (light green) is the only one registering 12v. ??

 

I'm planning on tapping into the light green for the power side and then either the green/white or the other green for the dimmer ground. Just need to figure out which is the dimmer ground now.

 

They don't show a reading when the lights are turned on??

Those are the 2 wires I used when I added a 2nd OEM fog light switch. Hmmm...

 

Nope. ?? (again im brand new at wiring so bare with me.)

1st scenario:
multimeter red terminal to the 3rd (light green) and black terminal to chassis grounded bolt. The only 12v register is the 3rd option. Other two green's register nothing at any time.

2nd scenario:
multimeter red terminal same, but black terminal to each of the other two green wires. They both show 12v's then as I'm assuming I'm closing the circuit at that point. So are they both considered grounds then? I tried moving the "dimmer" down and up to see if I could change the amount of voltage reading but no dice. 12v solid tho whole time on both 1st and 2nd wires. ??

 

Yeah... that's why I don't use volt meters. I use a test light for all my automotive wiring. It just tells you what has power and when. Run the volt meter between the 2 right pins the green and the green with the white stripe, and you should see a voltage change when you use the dimmer control.

Not trying to sound like an ass but you do have the lights on right?

 

ha yea I got the lights on. But seriously thanks for asking. When it comes to this kinda work I'd rather feel stupid now with something simple than stupid later with a burnt up truck.

I'll try that last option to look for a voltage change.

 

HOLY HELL I didn't have the lights on! I always leave my lights on as the truck will automatically shut them off after I park and lock it. Well my 2 yr old was playing in the front seat last night and well he likes to flip switches and move levers. Problem solved. Learned to never assume anything is where it should be.

So the verdict: 1. The light green wire (3rd from right in pic) is 12V only when the keys are in ign and set to "on". 2. The green/white (2nd) is the dimmer/ground and WILL register a drop in voltage as I move the dimmer switch (with the damn lights on of course). 3. The green (1st from right) is 12V but will only provide it if key to "on" AND lights on. So the light green doesn't have to have the lights on for it to provide 12v, just the ign to "on".

All set now! Thanks guys for chiming in and offering up help. I'm fortunate to have an unused and properly powered blank switch!

 

my truck has that same green plug behind that blank, i thought it was for the inverter but it would appear not. i wonder what its for? trac loc?

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cute EMB btw skywest??

 

Yea i'm not sure. Someone mentioned possibly for the differential lock option maybe. I've got the inverter on mine and it's in use on another switch.

Ha, yea it's a cute little airplane huh. ExpressJet. It's been a blast to fly but hopefully will be moving on up soon! Are you currently on the 73?

 

I think ur right diff lock. Looking fwd to seeing ur finished product.

Me too, xjt alum. 2001-2007, CO 73 now in EWR small world

 

According to the wiring diagram for the diff lock switch, you are correct. To be more specific, the light green wire is 12V switched from the IGN1 2 fuse, rated at 10 amps, and the red with black is the signal to the 3WD control ECU to tell it that the diff-lock switch has been activated. Also the dark green wire is the 12V dimmer controlled signal (For dimming the lights on the switches and designated as "ILL") and the green with white wire is the "ground" side of the dimmer, also designated as "ILL-"

 

Awesome, exactly what I have been researching today. Confirms what I finally figured out. Thanks for the info.

However I barely was able to make it through your post. Those boobies in your sig section are fantastic. So hard to concentrate!! Must stay focused!

 

Nice!! It is a small world! Especially in this freakin' industry. How are you liking it over there? I'm building PIC time as fast as I can. May have to go to Ord or Ewr to hold a line and be able to pick up more productive flying. This reserve crap in Iah just isn't doing it. Only 680hrs pic in a year down here.