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One of my rear lights in my 59 f100 HAs working turn signal and running light but brake light does not light. Replaced brake switch. Only uses two wires and brake and turn signal use same bulb. If turn signal is getting power wht is same bulb not working as brake light? Also changed entire light...still no brake light.
Any advice? Thanks Joe
Hi Joe,
Sounds like the problem is not in the brake light itself but in the wiring. Maybe check if you have 12v going to the brake switch itself. Thats all I can think of right now.
I had a similar problem after I got my '58 M-100 back from the installer, it turns out he had the wires switched on the Brake M/C. I un-plugged them & switched them around & the Brakes Lights came on right away when I step on the brake pedel now.
If it's anything like a newer setup, the brake lamp feed goes through the turn signal first ( so you can signal and brake at the same time). I'd check wiring at signal switch, or the switch itself. Hope that helps, Dev.
Brake and turn signal curent goes through the turn signal switch. Your problem is probably with the turn signal switch.
When you step on brake pedal and close the circut at the switch current is sent through the turn signal switch. If you move the turn signal switch to turn right the current from the brake light switch is cut off from the right bulb and the turn signal takes over the bulb. Same thing happens when you turn left.
Hope this helps.
As I stated Previously, It could be just as Simple as taking the Lower Brake Light Wire & the Upper Brake Light Wire that are Plugged into the Brake Master Cylinder & Switching them 'round.
That Is How I Solved My None Functioning Brake Light Problem.
If you Try that 1st & it Works, it could save You a Lot Of Trouble & Effort!
Did it work before you replaced the switch??? Did it ever work while you've had the truck?
Joe,
This is the key to the problem. If the brake and turn signal EVER worked then you may have a wiring problem causing it not to work now. But, if it didn't work before it may never work, because some directional signal switches are integrated and some are not. If you have the non-integrated type switch (5 wire), you will have to run separate lights for brakes and directional signals. The 7 wire integrated directional signal switch is needed to run brake lights and directional signals on the same light.
If they ever did work, then we need to go back and evaluate "everything" that has been done since they last worked and figure out what caused them to stop working. If they have never worked, then we need to start chasing grounds and voltage. I asked the question so we would know where to start, which should always be with the easiest and cheapest things first (again I hear my father speaking through me - they told me this would happen one day).