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68 mustang brake light problem

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Old Jul 25, 2008 | 11:39 PM
  #1  
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fanaholic
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Default 68 mustang brake light problem

Ok here is the deal. The brake lights stopped working but the turn signals and tail lights work. I replaced the switch and still nothing. The Connector is giving the switch power I checked this with a test light. When I press the switch down with my finger and complete the circuit while holding the test light on the metal part the completes the circuit, still nothing. No brake lights and no power leaving the switch. What should I do next?
Old Jul 25, 2008 | 11:42 PM
  #2  
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ky
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Default RE: 68 mustang brake light problem

replace the pig tail connectors on the back of the tailight buckets. theyre $20 each but they tend to give problems.
Old Jul 25, 2008 | 11:57 PM
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Default RE: 68 mustang brake light problem

Can you connect the two wires together at the switch to see if the circuit is intact. If the lights work then, you need to replace the switch again or look at the brake peddle to make sure it's activating the switch.
Old Jul 26, 2008 | 12:08 AM
  #4  
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fanaholic
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Default RE: 68 mustang brake light problem

Could the pigtail connector on the buckets be the problem if blinkers work. Its the same part of the bulb but im not sure. As far as the two wires are you talking about the ones connected to the plug at the switch.
Old Jul 26, 2008 | 12:28 AM
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Default RE: 68 mustang brake light problem

you didn't specify if you put the test lamp probe after the brake switch when you squeezed it. Putting the test lamp before the switch and then squeezing isn't any different than putting the lamp before the switch and doing nothing. If you close the switch and the lamp shows no power leaving the switch, then your replacement switch is probably bad too, it happens. If you have power leaving the switch, go to the connector at the tail light to see if you get power to the brake light circuit. You'll need a helper to press the brake pedal down or put a brick on it. If you don't get power to the circuit at the brake lamp assembly then your open is somewhere in between there and the switch. If you get power to that circuit at the brake lamp then you shout test the connector plug and maybe even the socket to the bulb. If you still don't find it then test the brake lamp ground leading away from the lamp.
Old Jul 26, 2008 | 02:03 AM
  #6  
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fanaholic
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Default RE: 68 mustang brake light problem

I stuck a wire from the power in to the power out on the plug and tested both sides with the test light and they light up. This would be like the brake pedal being pushed down correct? After doing this the brake lights still dont light. There are only two leads going into the brake lights and then a ground coming out. If my turn signals are lighting up then It wouldnt be anything at the bulb because its the same part of the tail light being used. Where does the power out wire go after it leaves the plug?
Old Jul 26, 2008 | 10:52 AM
  #7  
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Default RE: 68 mustang brake light problem

sounds like you're going to have to pull out a schematic and start tracking down the open. It's been a while since I've worked on a classic harness. If I remember correctly the brake switch wire goes into the exterior lighting/turn signal wiring harness under the dash... and then down under the carpet along or under the drivers side door sill...then up over the wheel well behind the quarter panel trim... into the trunk.
Old Jul 26, 2008 | 10:55 AM
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Default RE: 68 mustang brake light problem

I forgot... the pig tails at the tail light, I think one lead is for turn signal and the other is for the brake. If you turn on your turn signal and probe both leads you'll find out which one is the turn signal and which one is the brake. Then you can jump your brake switch again and see if you get power to that brake lead.
Old Jul 26, 2008 | 10:57 AM
  #9  
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Default RE: 68 mustang brake light problem

If you've tested as you say, and there's power into the switch, but not out of the switch, then the problem HAS TO BE the switch!
You could have gotten a bad switch!
Old Jul 26, 2008 | 05:28 PM
  #10  
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Default RE: 68 mustang brake light problem

After the brake switch the power does go to the turn signal cam switch in the steering column.



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