06 acura tl 545t headlight issue

I cant for the life of me find the damn headlight wire under the dash. Wiring diagrams from several places do not offer the wire, and Ive tested every wire at the switch & in a huge harness where I found the parking light wire with zero luck. Ive found a couple 545t installs in TLs on various forums but the wire colors they have are different and they had neg trigger wires, which I needed 12v to activate the parking lights. Anyone?Unless it raises the hair on the back of your neck, its only noise!

use a relay to invert the polarity of your neg. headlight wireAdvanced

The 545t uses neg trigger to activate a relay pack, the polarity of wire is not the issue. Finding a headlight wire is the issue, and I cannot find any wire that will activate the headlights.Unless it raises the hair on the back of your neck, its only noise!

Is there a headlight switch?  If so, one of the wires on it will control the headlights SOMEHOW! If it is a negative trigger, it will show 12v when the headlights are off, and switch to ground when the headlights are on. If this is the case, you need to have a negative output to power the headlights.  OTHERWISE, go to the cars relay panel, find the relay that controls the headlights, and interface to the positive output of the relay.

This info from Audiovox :

 Headlights-Lo     BLUE/RED  (+)      AT VEHICLE LIGHT SWITCH HARNESS

 Parking Lights     RED / BLACK  (+)     IGNITION SWITCH HARNESS 

This info from Bulldog Security ( Parking Lights only )  :

 PARKING LIGHTS ( - )     RED / BLACK (-)     @ HEADLIGHT SWITCH

 PARKING LIGHTS ( + )    RED / BLACK (+)    @ TOP of FUSE BOX, LARGE WHITE PLUG

This info from DEI ( Parking Lights only )  :

Parking Lights+     RED / black  +   dash fuse box, white 45 pin plug, pin 31  

Parking Lights-      RED / black  -    headlight switch in steering column cover

Definitely want to test with a DMM.  Check for a Blue/Red wire at the Light Switch, too.

Soldering is fun!

So at the headlight switch there are quite a few wires, and the parking light wire at the switch is + instead of - like all of the wiring guides specify. I thought it was odd to have every wiring guide I found specify neg when this car was clearly pos to activate parking lights. I did find a wire at the switch that could activate the headlights, which used a neg trigger to turn on the headlights however ONLY while the parking lights were on (with pos trigger). I could use this wire, but would prefer to have a direct tie to the headlights and not dependent on having the parking lights on too. The 545T offers a delayed turn off, which wont work because it flashes the parking lights while counting down the delay and if I used this wire at the switch the headlights would flash along with them. Not good for HIDs to flash them.

ac0j wrote: OTHERWISE, go to the cars relay panel, find the relay that controls the headlights, and interface to the positive output of the relay.

This is what I figured I would have to do, but hoped somebody would have specifics. Didnt spend too much time hunting around the car, instead tried to finish up the 5901 install.Unless it raises the hair on the back of your neck, its only noise!