Headlights stay on... with switch off

Discussion in 'Fox 5.0 Mustang Tech' started by will1992, Sep 23, 2010.

  1. Will a broken headlight switch make them stay on? I just took out my instrument cluster to replace a burnt out bulb. After i put it all back together, and plugged the battery back in, meanwhile my headlight switch was off, my guages were lit up and my door open bell was ringing. I unplugged the switch, and the lights go off, plug it back in, they come back on. I also cleaned my dimmer switch because it was not working before, now it works, could it be the dimmer switch? Wiring? I dont know.

    help is appreciated
  2. Apparently it can. You could remove the switch and do a continuity test between the feed and headlight output (with the switch turned off). It should read open circuit.

    Is this a 92 Mustang you're talking about?
  3. My headlight switch started doing this and I had to replace it. If you can pull back slightly on the switch (towards the off position) and the lights go out, it's your switch. Late Model Resto has an acceptable replacement:

    1987-93 Mustang Gt Headlight Switch, Reproduction at LRS - Same Day Shipping!

    While you are in there you might want to consider replacing your harness connector as well. Mine was fried and when that happens the connector distorts enough to allow the pins to pull out from the back. Then you have a mess.

    1987-93 Mustang Headlight Switch Connector, Assembled With 6" Wiring Pigtail at LRS - Same Day Shipping!

    I need a new connector for the hazzard lights / rear defrost switch for this same reason, but I have not seen a replacement for that yet.
  4. And if you have a GT, consider adding a relay to the fogs to help unburden the headlight switch.
  5. Definately. Do that first even :nice:
  6. Yes, it is a '92 gt vert,and the car doesn't have any fogs, they were removed by the previous owner. I will test my switch tomorrow. Thanks for the links, my headlight harness had some bare wires taped together with electrical tape too.:nonono: so, i'll be getting a new one along with the switch.

    thanks guys,
  7. Today, i tested my switch, and i pulled back on it while it was plugged in, and the lights went off. I thought, my switch is broken, but upon further examination of the switch i found that the plastic cover on the switch, has little tabs, which were broken. Those tabs had gotten stuck in the switch, so i got them out, had to take cover off, and it works. If you have a rattly switch then it's prob. not broken.