Electrical Brake lights don't work.

Discussion in 'SN95 V6 Mustang Tech' started by raven290, Jan 5, 2013.


  1. raven290

    raven290 New Member

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    So here's the problem.

    My brake lights don't come on. I checked the fuse in position 41 and the switch on the brake pedal and they're both good. I didn't see any voltage on the wires in the plug for the switch, but I'm not very handy with a multimeter so I may have just missed it some how. The bulbs themselves do work, seeing as my turn signals work and they light up when I turn on the headlamps.

    Here's my questions;
    1. Does anyone have a wiring diagram that shows the signal path for the brake lights?
    2. What voltage am I looking for and which wire in the pack is supposed to be the hot one?
    3. If no one has a wiring diagram, is there anything in the flow path between the fuse and the the brake switch?

    Thanks for your help.
    #1
  2. jrod2423

    jrod2423 Active Member

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    Is the ABS light on in your guage cluster in the dash
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  3. raven290

    raven290 New Member

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    No, but I don't have anti-lock brakes either, so I don't think I even have an ABS light.
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  4. wmburns

    wmburns SN Certified Technician

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    First, the post does not state the model year of your Mustang. But assuming this is a 99-04 MY, have you check fuse F2.33(15a)?

    I absolutely can help you with a full set of wiring diagrams and service manual for your car. PM if interested.
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  5. raven290

    raven290 New Member

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    Sorry, It's an '02 V6 for anyone interested. I'll check that fuse and get back to you in a little bit.
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  6. raven290

    raven290 New Member

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    Checked f2.33. It was good. I checked all my other fuses while I was at it and none of them were blown.
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  7. wmburns

    wmburns SN Certified Technician

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    From a circuit point of view, there is a direct path between fuse F2.33 and the LG/RD wire of the brake pedal switch. Soooooo assuming there is source power to F2.33. And F2.33 is good. And there is no power at the LG/RD wire at the brake pedal switch, then there must be a wiring harness fault.

    I suggest that you go back and double check your work. A mistake here could cause you to go on a wild goose chase.
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  8. raven290

    raven290 New Member

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    So here's an update. All my fuses were in good working order, so I checked the power to the brake switch. It was present on the always hot side and showed up on the other side when the switch was depressed. There was no power at the connector for the brake lights through out all of this. I was thinking it was possibly a broken wire between the lights themselves and the brake switch. Recently, someone suggested that it may be the multifunction switch. I'm going to try to replace that and see what happens. Updates to follow.
    #8
  9. raven290

    raven290 New Member

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    I'm having trouble finding a 99-04 mustang at junkyards near me.I have found several 94-98s though. does anyone know if the 94-98 and 99-04 models have the same multifunction switch?
    #9
  10. wmburns

    wmburns SN Certified Technician

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    Go to car-part.com and enter your make/model/year and the part you are looking for. The search engine will show a list of "other" applications with similar parts.

    Many Ford products use the same multi-function switch. Including the Grand Marquis, Crown Vic, and Town car. Note, the stalk may be different while the switch on the inside is the same.

    Note, the multi-function switch can be rebuilt. Clean, lightly sand, and re-grease all contacts with di-electric grease. Take pictures!
    #10
  11. dgoggans7972

    dgoggans7972 Member

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    try CJPony.com.... i have found several odd bits like convertible rubber and tag light housings that are hard to find... those switches do go bad.... the switch is more likely to be the culprit than the wiring.....good luck
    #11

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