No brake, signal or hazard lights

Tiny
TIM NUMMY
  • MEMBER
  • 2000 FORD F-250
  • 7.3L
  • V8
  • 2WD
  • AUTOMATIC
  • 290,000 MILES
I have checked all the fuses and changed the multi-function switch. No help.
Sunday, May 15th, 2016 AT 12:54 PM

14 Replies

Tiny
CARADIODOC
  • MECHANIC
  • 33,873 POSTS
Check for 12 volts on fuses 1 and 13 in the fuse box inside the truck.

Does the horn work?
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Sunday, May 15th, 2016 AT 1:24 PM
Tiny
TIM NUMMY
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Power to both fuses and the horn works.
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Sunday, May 15th, 2016 AT 1:49 PM
Tiny
CARADIODOC
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Next, check for 12 volts on the light green / red wire at the brake light switch. If you have it there, push the brake pedal, then check on the light green wire.
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Sunday, May 15th, 2016 AT 2:00 PM
Tiny
TIM NUMMY
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I have power to the light green, and power to the light blue pin 44 on the multi-function switch also.
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Sunday, May 15th, 2016 AT 3:18 PM
Tiny
CARADIODOC
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Now hold on a minute. You have multiple circuits that are not working, that are fed from multiple places. What they all do have in common, it appears, is the grounds. Does your center high-mount brake light work? That is the only one that has a ground that is not shown on my diagram. The rest all appear to be grounded at the "left rear of the vehicle".

Check for voltage on the light green / orange wire at the left rear brake light bulb, and / or the orange / light blue at the right side, with the brakes applied by a helper. (I use a stick between the seat and the brake pedal to gold the pedal down). If you have voltage to those places, it is the ground wire you have to follow. Ford likes to bolt a number of ground wires to the same stud, so if that terminal corrodes off, you will have a number of dead circuits.
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Monday, May 16th, 2016 AT 8:01 PM
Tiny
TIM NUMMY
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No power from both sides.
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Wednesday, May 18th, 2016 AT 6:17 PM
Tiny
CARADIODOC
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Okay; double-check that you have voltage on the light green wire at the signal switch when the brake pedal is pressed. Next, check for 12 volts on the white / red wire, also at the signal switch. The first is the 12 volt feed from the brake light switch. The second is the hazard circuit feed from the flasher assembly.
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Wednesday, May 18th, 2016 AT 6:43 PM
Tiny
TIM NUMMY
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  • 9 POSTS
Light Green yes, White/Red NO
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Wednesday, May 18th, 2016 AT 7:15 PM
Tiny
CARADIODOC
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Check on the light green / orange and the orange / light blue coming out of the signal switch, both when the brake pedal is pressed.
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Wednesday, May 18th, 2016 AT 7:27 PM
Tiny
TIM NUMMY
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No, Neither one lights up.
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Wednesday, May 18th, 2016 AT 7:33 PM
Tiny
CARADIODOC
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Gotta be a bad signal switch or there's a different problem and the hazard switch is turned on. You can verify this by jumping the light green to the light green / orange wire. That should make the left rear brake light work.
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Wednesday, May 18th, 2016 AT 7:40 PM
Tiny
TIM NUMMY
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MMMM Interesting. I tried the jumper, but both brake lights came on. And after taking the jumper wire out, I step on the brake and nothing comes on, but if I push down on the hazard switch, both brake lights come on.
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Wednesday, May 18th, 2016 AT 7:53 PM
Tiny
TIM NUMMY
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Man, what a freekin mind bender!
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Wednesday, May 18th, 2016 AT 7:55 PM
Tiny
CARADIODOC
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Check the signal switch connector for stretched or corroded terminals. That's right for both brake lights to come on. The signal switch ties them together when the signals are off. I forgot about that.
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Wednesday, May 18th, 2016 AT 8:03 PM

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