Brake lights always on
Thread Starter
|
Freshman User
Joined: Mar 2012
Posts: 35
Likes: 0
From: San Diego
Brake lights always on
Need help. Have a '68 F100 flareside. My brake lights are always in the "brake" position, meaning it looks like I'm standing on the brakes. This only happens when I also have the lights on, even in the parking light setting. So I spent the last two days re-wiring from the fire wall to the tail lights. Found some mushy 4-wire connections in the bay, fixed them too. Put a new fuse in, turned on my lights, turned my key to ON. Had turn signals at this point. Hooked up my brake switch with my finger on the plunger keeping it off. Let fly on the switch and the 20A fuse blew. Began chasing wires thru the dash, but it's getting dark and I can't think straight after chasing this ghost in the machine. I read the other posts and someone suggested the turn signal switch. Is this correct? With the blown fuse I have ON brake lights, none if the key is off. Hook up the brake switch, and either blow a fuse or start a fire if I try to jump or tin foil it. I need help, this is driving me crazy.
Thanks,
Joe
Thanks,
Joe
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
I would investigate the turn signal switch. Maybe unplug it and test the wires. With no power, see if you get any leads to go to ground with an ohm meter.
There are only 4 wires going to the rear of the truck for the lights to function, so if you fixed that already, then it is likely inside the truck.
There are only 4 wires going to the rear of the truck for the lights to function, so if you fixed that already, then it is likely inside the truck.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Joe to add to FT, have you done any work on the electrical anywhere on the truck?
You might want to check at the master cylinder, with the ign switch on, one wire should be hot the other not, if both are hot the brake light switch is bad, allowing current to pass at all times.
John
You might want to check at the master cylinder, with the ign switch on, one wire should be hot the other not, if both are hot the brake light switch is bad, allowing current to pass at all times.
John
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 785
From: Simi Valley, CA
F100. This switch was used on 1969/72 F100/350's only. So, you either have a 1969 F100, or someone changed the brake pedal.
1967/68 F100/350 uses a totally different switch. Pushrod has a hole in it, switch (it's rectangular) has two holes, pushrod fits in between them.
Bolt passes thru switch-pushrod-switch then thru hole in brake pedal, nut retains it.
Post the last 6 digits of the VIN, this will verify the year.
Thread
Thread Starter
Forum
Replies
Last Post
Josethef100
1961 - 1966 F-100 & Larger F-Series Trucks
21
Jul 14, 2019 06:19 PM
hrp77573
1961 - 1966 F-100 & Larger F-Series Trucks
6
Sep 18, 2010 06:09 AM
