hey i need to know which wire on the headlight/turn signal switch harness is connected to work the high beams. I'm wanting to connect a relay to that wire so that my off road lights will turn on with the high beams. Any suggestions?
On 2005 and newer E/M/Ts, the controls are low-current inputs to the Smart Junction box. The controls have no direct connection to the lamps, and it's not a good idea to connect high-current circuits to them.
If the relay coil doesn't take much current, you're better off connecting it in parallel to one of the high-beam bulbs.
alright well do you happen to know of any place where the high beam wire is easily accessible for tapping, such as where it leads through the fire wall? I've looked around the headlight casing and can't find where the wiring leads into them.
Luckily, one side of your relay coil can connect directly to ground. The other side of the relay coil can connect to either one of the two separate high-beam wires, which are inside a harness that goes directly from connector C2280B on the Smart Junction Box to the connectors on the headlamps.
The Smart Junction Box contains the fuses, and it's inside the front of the console:
jpark, its appears you are very knowledgable about the headlamp circuit, hopefully I can pick your brain about something probably simple for you. I just purchased an 05 Mercury Marniner 3.0L 2WD no auto lamps no DRL's. The headlights (low and high) just randomly turn off. The marker lights still stay on... I am still able to pull back and hold on the headlamp switch to activate the highbeams but then poof within a few minutes they start working again. Everyone tells me it must be the headlamp switch but I am hesitant as everything works when I try to test it. I was able to wiggle the harness down near the fuse block (C2280B & C) and they flickered but again it only happened breifly. One last thing, where is the headlmap relay on this vehicle? I pulled every relay on the back of this fuse block and the ligths still worked.