• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-

Electrical help! 03 mustang headlights

  • Thread starter Thread starter Itsjustapigron
  • Start date Start date Dec 14, 2018
  • Tags Tags
    2003 headlamp headlight wiring
I

Itsjustapigron

New Member
Dec 14, 2018
1
0
1
Louisiana
Dec 14, 2018
#1
  • Dec 14, 2018
  • #1
So I just installed the “white face reverse glow gauges” and my turn signals work but my headlights (low and high beams) don’t work. Also, I can use the “flash to pass” and my lights come on.. don’t know what to do
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Dec 15, 2018
#2
  • Dec 15, 2018
  • #2
I give up. What model year Mustang are we dealing with here?

IF we assume this is a 1999-2004 model year, then double check fuses F1.2, F2.38, F2.10, F2.4.

1999-2004 MY fuse panel schedule:
https://www.allfordmustangs.com/for...r-swap-wont-fire-please-help.html#post2669271

Next we have to confirm power out of the the head light switch RD/YE wire with the head lights on. Note, there is a circuit breaker inside the head light switch. Plus the head lights switch does fail after many years of service. Look for evidence of over heating.

Next check the electrical connector to the multi-function switch to be sure it's fully seated.

What to do next depends upon the test results.
 
Last edited: Dec 15, 2018
Reactions: Kenestacio
K

Kenestacio

New Member
Aug 2, 2020
1
0
1
NYC
Aug 3, 2020
#3
  • Aug 3, 2020
  • #3
wmburns said:
I give up. What model year Mustang are we dealing with here?

IF we assume this is a 1999-2004 model year, then double check fuses F1.2, F2.38, F2.10, F2.4.

1999-2004 MY fuse panel schedule:
https://www.allfordmustangs.com/for...r-swap-wont-fire-please-help.html#post2669271

Next we have to confirm power out of the the head light switch RD/YE wire with the head lights on. Note, there is a circuit breaker inside the head light switch. Plus the head lights switch does fail after many years of service. Look for evidence of over heating.

Next check the electrical connector to the multi-function switch to be sure it's fully seated.

What to do next depends upon the test results.
Click to expand...

This was really helpful, thank you. Everything was fine on my ‘03 V6 but the low beams suddenly stopped working. Whipped out the multimeter, no power to the headlight low beam harnesses, but the fuses were all fine, 4 and 10 had power, all grounds fine, no visible breaks or cracks in the wires or main engine harness.

Opened the headlight switch, the switch wiring harness was cracked and burnt around pins B1 and B2 (dark blue/orange, and tan/white), replaced the harness, yay thought I was done—#$%! nope, headlights still dead. Then installed a new switch. Nothing.

Started calling mechanics, got “Nah, we don’t do electrical, call a body shop.” Called body shops, finally was sent to Gus. You know Gus, we all know Gus, he’s a true master. Gus says, “Sure, I’m free Wednesday, bring it on down. $140/hour.” :::record scratch:::

Saw your magical post, wondered what the multifunction switch has to do with the low beams, but opened it up and I had forgotten about that little C202b connector, sure enough, it was throughly toasted. The two red/yellow pins (2 and 3) were falling out the back. A new one is on the way, but meantime I‘ve shoved the pins back in place and voila, the low beams are working fine.

Thanks again.
 
You must log in or register to reply here.

Similar threads

1
Electrical Headlight harness trouble
  • 1985fox
  • Apr 14, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
198
Fox 5.0 Mustang Tech Apr 17, 2026
AeroCoupe
2
Electrical mayhem
  • 2000ElectricGreen
  • Mar 13, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
2
Views
220
1996 - 2004 SN95 Mustang -General/Talk- Mar 24, 2026
2000ElectricGreen
2
J
Electrical problem with headlights
  • jeremykrell308
  • Oct 22, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
5
Views
252
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 3, 2025
General karthief
T
2002 V6 3.8L Help Me
  • TheIncompetentMechanic
  • Apr 4, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • 2 3
Replies
50
Views
698
1996 - 2004 SN95 Mustang -General/Talk- May 12, 2026
TheIncompetentMechanic
T
1
Electrical 1985 mustang gt Led conversion trouble
  • 1985fox
  • Jan 5, 2026
  • Fox 5.0 Mustang Tech
Replies
10
Views
558
Fox 5.0 Mustang Tech Jan 15, 2026
1985fox
1
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?