Changing Headlights. -

GT S197 General Discussion This section is for technical discussions pertaining specifically to the V8 variation of the 2005 and newer Ford Mustang.

Changing Headlights.


Old 08-11-2018, 06:47 PM
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Default Changing Headlights.

Hey guys, I'm trying to change my 4 prong connector female end to a 3 prong female so I can connect to my new headlights.

Does anyone have a wiring diagram or know which wire is which for when I do the splicing? I cannot seem to find any information anywhere.
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Old 08-12-2018, 01:03 PM
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Old 08-12-2018, 03:13 PM
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My 2008 only has three wires, Ground, Lo, and Hi beam.

The diagram for the 2005, also shows three wire harness, not four.

The harnesses plug right into the back of the bulb, so, don't know what
you have there for four wires ...
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Old 08-13-2018, 02:31 PM
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Do you have HID Lamps? HID wasn't an option until 2007 or 2008 so the 2005 workshop manual won't help you. I've had the headlights out for replacing a ballast but I don't recall the number of wires it had.

This is the 2011 diagram

It looks like your car with 4 wires.

Last edited by Derf00; 08-13-2018 at 02:35 PM.
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Old 08-13-2018, 03:59 PM
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The HID bulb stays the same intensity, the shutter is what determines LO and HO beam.
On a NON HID capsule, the low beam element is turned off when the hi-beams are
switched on. SO, when you add an aftermarket HID, they have a solenoid system that
pulls the bulb back to expose more of the light onto the reflector, but the brightness
never changes.

This is the same on factory HIDs, the shutter opens all the way for hi-beam, then partially
closes for low, the bulb brightness never changes.

You will need more than the 3-prong harness to change over to an incandescent bulb.

You will retain the ground, no change there.

Lo-Beam wire will need to go through a relay - pin 30 to 87a, to the lo element, then pin 86 to ground.

Hi-Beam shutter line will need to go to pin 85 of the lo-beam relay to turn them off when HI beams are
selected, then another relay, to activate the hi-beam element in the bulbs... The factory halogen lighting
is done in this manner, when you turn the hi-beams on, the low beams turn off.

If you wire it in without the relay to turn off the LO elements, then your HI and LO elements will be on with
hi-beams on. I am not not sure the housings can take the temperature of both 55 watt and 65 watt elements
being on, for 120watts of light in each housing. If it can, then good, you just have 120 watts of light with
the hi beams on, and 55 watts lo-beams.
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