[mswscco]

I originally posted this over on the Sequoia side but didn't get any response, so...

Is there a headlight switch wire in one of the factory harnesses behind the radio? I just installed a Pioneer nav unit and want to tap in for auto day / night screen adjustment. Thanks.

 

[mendonsy]

The Sequoia wiring should be close to the Tundra I guess. I think that ThirdHorseman would know for sure. If you are looking for a 12 volt signal I suspect you are out of luck. Here's the wiring diagram for a Tundra:

 

[Someguy123]

good question. ive been chasing this question for awhile now. ive just been too lazy to pull the dash apart, and use my meter to find out which wire it is.

its going to depend what stereo you have. i have the JBL with stock NAV. there is garunteed to be a headlight signal back there, to dim the stock head unit. but on a basic CD player head unit, you might have to tap off the wire in the kick panel.

 

[mendonsy]

There are two 7.5 amp fuses that apparently come from the ignition and go to the accessory meter above the radio. Maybe one of those would work??
accessory-meter.pdf

 

[Jerryh3]

Do you want the headlight switch wire or parking lights? There should be an illumination wire in the stock radio harness that is triggered from the parking lights.

 

[FUNGUS]

Every toyota has been wired the same for a radio (all models) since like 1988 or something like that. You use the dimmer wire on the harness. Just wire your adapter to the pioneer harness then plug it in and you are good to go. I am pretty sure all aftermarket harnesses are the same so it should be an orange wire, says dimmer. This wire works with ALL Pioneer units.

 

[Someguy123]

Every toyota has been wired the same for a radio (all models) since like 1988 or something like that. You use the dimmer wire on the harness. Just wire your adapter to the pioneer harness then plug it in and you are good to go. I am pretty sure all aftermarket harnesses are the same so it should be an orange wire, says dimmer. This wire works with ALL Pioneer units.

if you use the scochse adapter harness it has no wire for dimmer. you need to directly hook the dimmer wire from the head unit, to the correct wire behind the dash. which would be the wire we are looking for.

 

[mswscco]

I had the non nav JBL and have to power speakers off the RCA outputs so I'm not using an adapter between the nav and factory harness. I manually tapped the factory harness for constant / accessory power as well as speed (several write ups identifying these wires). The harness that came with the nav does have an orange dimmer wire, just don't know what to connect it to.

I know the factory nav auto dims at night and unless it's got a light sensor I'm guessing there's a headlight wire in one of the radio harnesses back there. Hopefully it's there for non-nav model vehicles too and someone knows which one it is. Really appreciate the input so far.

 

[FUNGUS]

if you use the scochse adapter harness it has no wire for dimmer. you need to directly hook the dimmer wire from the head unit, to the correct wire behind the dash. which would be the wire we are looking for.

Errr.. wrong... like I said before, its the orange wire..... on your SCOSCHE adapter....

Scosche TA02B - Wiring Harnesses - Sonic Electronix

 

[mswscco]

Okay, just ordered one of these. They're only 6 bucks and I should have done this in the first place instead of cutting the factory wires. It looks like the orange wire goes to either pin 4 or 12 on the factory harness. If someone can confirm that is the illumination / dimmer wire, I should be good to go. Otherwise I'll give an update after it's installed.

Errr.. wrong... like I said before, its the orange wire..... on your SCOSCHE adapter....

Scosche TA02B - Wiring Harnesses - Sonic Electronix

 

[FUNGUS]

First off, take harness from Pioneer head unit and wire to LABELED pieces on SCOSCHE harness. Everything is labeled. It is simply check and crimp. Then plug scosche harness into factory plug and the other end into the Pioneer unit. Do not cut anything in truck....ever....

 

[Someguy123]

Errr.. wrong... like I said before, its the orange wire..... on your SCOSCHE adapter....

Scosche TA02B - Wiring Harnesses - Sonic Electronix

what is that harness for, im guessing its for the basic cheap stereo?? this is the harness i have, its for the JBL system.

Scosche TA07SR - Wiring Harnesses - Sonic Electronix

 

[mswscco]

The TA02B harness won't work if you have the JBL system. I already had one of these installed...

Amazon.com: 07-09 TOYOTA DIGITAL AMP TURN ON INTERFACE: Automotive

...and never noticed the nice orange wire hanging off of it. Turns out that's the one. I didn't think it would be on a different bundle from the power / speed harness. Maybe those signals are duplicated here too, I'm not sure. In any case, now everything works. The dimmer wire on the adapter goes into this pin here:

 

[Someguy123]

The TA02B harness won't work if you have the JBL system. I already had one of these installed...

Amazon.com: 07-09 TOYOTA DIGITAL AMP TURN ON INTERFACE: Automotive

...and never noticed the nice orange wire hanging off of it. Turns out that's the one. I didn't think it would be on a different bundle from the power / speed harness. Maybe those signals are duplicated here too, I'm not sure. In any case, now everything works. The dimmer wire on the adapter goes into this pin here:

just to clarify, do you have the JBL or base stereo??

 

[mswscco]

I have the JBL

just to clarify, do you have the JBL or base stereo??

 

[Towerboss]

Can someone please tell me if a 2007 Toyota Tundra headlight/high beam is a positive or negative switched system? Also, does the Tundra have a common wire between the two lamps?

Thanks
TB