07 foglights wire colors under dash.

Where do find the fog light wires under the dash to connect to, to add my aftermarket switch.?

 

Here is the link to an awesome thread created by @RainMan_PNW

https://www.tundras.com/threads/ultimate-tundra-wiring-diagrams-collection.81448/

 

Can you explain a little more about what you are trying to do? You say aftermarket switch meaning either you don’t have the factory one or you just don’t want to use it anymore.

What is the overall goal? Also what year is the truck? Wire colors vary by year somtimes.

 

I've been installing aftermarket foglights on 07 tundra crewmax SR5, I'm trying to use all the existing wires, which it has everything but the switch, the actual fog lights, and the relay.
..I've installed the 2 in 1 LED fogs, the relay, and a push button switch ( in a blank next to the button for Trac control)
....I watched the wrong guy on YouTube
....I have a 4 pin switch wired in, and it is lighting up, but not the fog lights.https://youtu.be/OQiFLtb-mnU

this is the youtuber I followed in wiring the fogs up. something definitely went wrong.

 

the left side is the top. here is my new fog light switch I'm trying to use instead of the switch knob from toyota

 

Two wires on that switch are solely for backlight - I’m guessing the green and black but it could be orange and black (hard to tell if the two middle wires are both red or one red and one orange). One is +12V illumination (like when headlights are turned on) and the other is ground.

The other two wires are simply the switch circuit - one comes from your switch power source (either battery or ignition) and the other goes to the relay coil.

I’m on my phone so I can’t pull up the EWD for the fog light circuit in the 2007, but I’m 90% it’s just a standard relay circuit (the 2018+ now uses the ECU to fully control things).

 

This is the factory fog light diagram. Turning the fog light switch on sends a ground signal into the main body ecu on the pink wire. That ground signal then comes out of the blue wire (signal wire to relay) on J4 Pin#4 to the fog light relay. You have to send a negative or ground signal on this wire to make the relay close and turn the fogs on.

The green wire coming into the bottom of the relay is the power side and its come from the tail light fuse. This is why the headlights have to be on for the fogs to work. If they are not on the bottom side of the relay will not have power and it will not function.

Make sure you have the 15A Fog Fuse in, I labeled it as power to the relay but its really power through the relay to the fog lights.


As Casey said your switch will have 4 wires. Two are for the illumination circuit and it sounds like you have those working. For the other two wires, one needs to go to the blue wire coming out of the body control module. The other goes to ground, so that when the button is pushed it connects these two wires together.

Tying into the blue wire bypasses the Mainbody ECU which gives more freedom in operation. The fogs will stay on with bright headlights now ect. The factory wiring put the switch on the pink wire but that gives more restriction control to the main body ecu.

You want to use J4 Pin#4 Blue wire as your trigger signal wire to the relay.

 

Thanks Jeff - that is exactly what I was planning on pulling up and doing/explaining.

Only "nitpick" on that would be technically the arrows in the ECU would go the other way...the foglight switch is completing the ground for the relay to activate, which will only happen if both the switch is on AND the ECU closes the internal circuit (i.e. high beams are off).

 

so I should use a ' quick connect" and tie into the blue j4 pin4, not cut it? correct.
....and go to a ground point with the other wire?
( I'm a poor electrician, please excuse me.)

 

Either way would work, you just need to take that wire to ground to trigger the fog relay. You won’t be using any function from the main body ecu, it’s not needed.

You can easily test by just connecting the blue wire to a ground point with a jumper. If you have the relay and fuse correct the fogs should come on. Make sure the headlights are on when you test.

Then you just wire the switch in to take that wire to ground when you push the button. One leg of the switch is the blue wire, the other a wire to a good ground location.

 

ok, I was making it harder than it should have been.
...wish me luck.
I'll be back at it, and hopefully almost done this weekend.
...I'm always off on Sun mon Tues, so that will give me plenty of time to finish this project.
Thanks again! This Tundra forum is the best!

 

Hardest part now should be making sure you have the right blue wire and that you properly understand the 4 wires of your switch.

Post any more questions you have and remember adding pictures really helps.

 

it's the skinny light blue wire, I think I've got it. With the connector and pin #, I should have a good start.

 

Here! This is a spare from a 2014 I had easy access to in my garage. It should be this blue wire. Being this is from 2014 every wire color may not match yours fyi

 

ok only the driver side
led foglight came on
.....I will hafta back track, loose something

 

...#1 Thanks for helping so many of us,
#2 my "plug n to factory" LED foglights are in, 4 pin switch works, but.... only the driver side foglight comes on.
( just thought I'd pick your brain before heading out to the gerage.. any thoughts, or pointers would be appreciated
thanks...

 

If drivers side is working the relay, fuse, switch are all working. You just have an issue somewhere between the relay and the passenger side bulb.

I would turn on the fog lights and check for voltage with a voltmeter at the connector to the passenger side. If you have 12v the issue is with the lamp, bulb, connector to the lamp.

 

10/4
...Several days ago, I went ahead and ordered a pack of new Toyota male and female fog light harness extensions, in thinking I might have a bad connection at the fog light. 8 dollars, i couldn't pass it up.
I'm headed out to test the voltage now.

...one more question, the white wire, would I need to wire it to the ignition fuse, via fuse tap, to have the halo as a DRL?

 

I have power at the fog light harness on the tundra harness, but led still doesn't work, nor do the halo rings around either light. I have a fuse Tap into ignition 10 Amp fuse.
....instead of the halo rings lighting up, the driver side fog just stays on..
...I think I might have got bad lights.

 

Double check your ground and power connections.

If you don’t have a good ground then the halo won’t work even if power coming from the fuse

 

I took the left light out and tested it on a 12 v battery and it worked great. ( even though my light last night showed power at the harness, it still wouldn't light up when I plugged them back in)

...I'm thinking I might just back track and wire them on their own harness then into my switch.
...I used male and female quick connects just incase I had to back up. I'll plug everything back into factory place.
I still want to tinker a Lil using the factory wires before throwing in the towel and using the other harness.
....just curious, would a bad wire tap, quick connect, where I spliced into the blue wire under the dash cause this.
..
also, I should just tie the halo light on each fog, to the +wire on its fog light nstead of trying to configure Drl. you think? The lights look really nice with all 4 leds lit up inside. I'm still deciding.
Hopefully I'll get a lil down time at work to go back through it. otherwise it will hafta wait until sunday.

 

I think you might still be confused about the operation of the factory wiring and circuit.

If one of the fog lights is coming on when the head lights are on, all of the wiring to the switch and relay is correct. The last step is for the power to spilt off to both fog lights. If you have power to one side you should have power to the other. The only reason not to would be a broken wire between the factory connector and the relay.

Have you verified 12v at the factory harness connector on both sides with a volt meter?

I would be looking closely at the connector that plugs into the fog light that is not working.

Can you post some pictures of the back of the lights/wiring you are using as well as the factory connector.

I would focus on getting the fogs to work first the in the factory mode, then worry about adding the DRL halo. Seems you still have connection issues at the factory harness to fog light location

 

I just used a test light, the battery in my old multimeter was dead . I got a new 9 volt last night, and yesterday arrived my two brand new Toyota extensions.
....I got the extensions, that way I would have 2 males and 2 females to use, I ordered them on a whilm.while.. if I need to ill just snip the extension and use which ever I need.
....would a poor ground cause the one light to not work. I need to trace the wires up and toward the relay from the bumper. ( they did look kinda rough)
I'll post pics. thank you for your helpful advice

 

Yes a bad ground essentially cuts the circuit in half and it won’t work.

A volt meter on the ground and power pins is the best way to test both. You need 12v

 

If you look here you will see the power splits off from a red wire coming out of the relay to a blue and pink wire. One side will be blue the other side pink. These are the power wires. Both ground are black/white and join back up to a single ground location.

Focus on verifying operation of these 4 wires first. Then we can look at adding the halo light

 

that's great help. it is the pink side, that's the pass side fog, I'll get that done, asap. ( I do go back to work today through Sat evening, but stand by, I'll post pics of what I'm doing.)
...I felt alot better last night after I put 12v direct to the fog light I thought was bad, and it worked great, even the halo.
thanks again and I'll be adding another post w/pics.

 

i

 

I cleaned my contacts and realized did a couple male/female connections. It worked!
both fog lights come on with a switch on all light settings, parking,low,and High
thanks men!

 

ok, I just replaced my headlight assys and I need to jump back down to those foglight halos.
....any suggestions?, I'm still up in the air, on what to do with them.

 

What do you want to do with them could more so be the question? I think alot of people just run them off the ignition fuse so anytime the key is on they are on.