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Break lights suddenly stopped working and my friend said its almost like something was reversed, never touched the wiring and now my break lights will only come on when you put on the hazards, its an 86 f150 5.0 efi c6 auto 4x4
Repair the grounds in the rear of the truck. Depending on the year will there can be up to 5 grounds for the rear lights. There locations also vary by year. 1980 there is a ground behind the light in addition to 5 more on the rear frame rail.
Look at the diagram with the red arrows, showing the brake light action. Compare with the diagram with green arrows, showing the 4-way hazards. When you turn on the 4-way hazard switch, power to the rear bulbs follows almost the same path as when the stop lamp switch is activated (by the brake pedal). The big difference is the hazard switch bypasses the stop lamp switch.
Based on that, I'm almost positive either your stop lamp switch has failed or the wires broke next to the switch. If the wires look good, try jumpering across the terminals on the stop light connector. If the brake lights now illuminate, the switch is bad. If not, you may still have broken wires inside the insulation, but it isn't apparent. Check continuity with an ohmmeter.
Don't forget to update your thread with what you find, to help the next guy.
Repair the grounds in the rear of the truck. Depending on the year will there can be up to 5 grounds for the rear lights. There locations also vary by year. 1980 there is a ground behind the light in addition to 5 more on the rear frame rail.
I thought we ironed this out in another thread? Several grounds if you have a flare side or a dually wide side, but on a regular pickup the ground is up front behind the radio, not at the back of the truck.
I thought we ironed this out in another thread? Several grounds if you have a flare side or a dually wide side, but on a regular pickup the ground is up front behind the radio, not at the back of the truck.
The 80 & 81 and maybe the 82's do not have that ground from tail lights to the front like the later years.
There are grounds at the tail lights. You remove the light housings and there is a screw with the ground wire right there.
That is how my 81 style side was.
Here is a link to my picture of the style side tail light harness un-taped so I could use it for my flare side.
If you click on the picture it gets larger and on the left side you can see the ground wire loop. The right side is on top of a socket. 20191012 093706
Dave ----
Break lights suddenly stopped working and my friend said its almost like something was reversed, never touched the wiring and now my break lights will only come on when you put on the hazards, its an 86 f150 5.0 efi c6 auto 4x4
i don't know if it helps but everything only works if the lights are off so at night its hand signals
i don't know if it helps but everything only works if the lights are off so at night its hand signals
Have you worked through the troubleshooting guide, linked in post #4 above? Specifically, do the part where you operate all the lights while parked in a dark location. I suspect you may see some other lights illuminate dimly when they should be off, which points to a bad ground.
Could be you’ve got two faults going on at the same time, such as also having a bad stop light switch.
Break lights suddenly stopped working and my friend said its almost like something was reversed, never touched the wiring and now my break lights will only come on when you put on the hazards, its an 86 f150 5.0 efi c6 auto 4x4
nevermind just found out that whoever wired this thing deserves to be shot, a wire was not connected properly
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