brake lights not working still

88beast

Full Access Member
Joined
Sep 23, 2009
Posts
2,219
Reaction score
1
Location
pa
ok now i have a new brake light switch new sockets and a new turn indicator switch
still no brake lights
both signals work
and markers still work
i need a wiring diagram or somewhere to look more in detail
i know it goes from batt to brake light switch then either to
turn switch
or direct to brake lights
i have no power at the lights or where i replaced all the trailer wiring today
thanks
 

bigblue85

Full Access Member
Joined
Feb 1, 2011
Posts
340
Reaction score
5
Location
Vallonia/IN/USA
ground. or you got a wire that the outer coating has rubbed off somewhere and is causing a ground or ohm jump from one wire to another that could have the outside wore off. is there any fuses or relays popping?
 

idi traveler

Full Access Member
Joined
Dec 13, 2009
Posts
768
Reaction score
0
Location
Brashear, Texas
The ground to the bed should be good because the other lights work. Are the any splices in the brake light circuit? I was working on an F150 a few weeks ago that the tail lights didn't work on it. I found three splices in the power wire(crimp style). I soldered a new piece of wire in bypassing the splices and it fixed it. Take a look, you have nothing to loose!
 

88beast

Full Access Member
Joined
Sep 23, 2009
Posts
2,219
Reaction score
1
Location
pa
well i know from cab to lense the turn and brake work on the same wire and filiment so it got to be something in the cab but i got so many wires under there with all my mods its a nightmare plus work the po did makes it worse
 

franklin2

Full Access Member
Joined
Feb 24, 2009
Posts
5,161
Reaction score
1,385
Location
Va
The power for the brake lights leaves the fuse, and then goes to the brake switch on the brake pedal. I would check for power at the brake pedal switch. You should have power all the time(even with the key off) on one side of the brake pedal, and both sides when you push on the pedal.

After the brake pedal the wire goes to the column and then up to the turnsignal switch. It goes into the switch as a lightgreen wire. The switch co-ordinates the brake lights with the turn lights, since they are the same thing. So if the turn switch is in the center, you should get 12v on the lightgreen going into the switch, and 12v on both the lightgreen/orange and the orange/lightblue wires which go back to the rear lights.
 

88beast

Full Access Member
Joined
Sep 23, 2009
Posts
2,219
Reaction score
1
Location
pa
thank you thats what i was looking for so i need to check the turn switch i have 12 at the bl switch when presses
 

idi traveler

Full Access Member
Joined
Dec 13, 2009
Posts
768
Reaction score
0
Location
Brashear, Texas
Does the wind shield leak over the column? Mine did and it caused the po all kinds of problems, and then me. It turned out that some of the contacts in the turn indicator were corroded. A whole lot of wire repair later and then a turn switch all of my lights on my truck worked. That was over a year ago, been trouble free ever sense. I guess I'm say'n, if everything else is good, it's time for a hard look at the turn switch. $45 at O'Riely's
 

88beast

Full Access Member
Joined
Sep 23, 2009
Posts
2,219
Reaction score
1
Location
pa
ya i just put a new switch in but im going to look into it later today hopefully
 

Cubey

Van dweller
Joined
Oct 18, 2017
Posts
4,066
Reaction score
1,580
Location
USA
If you have a T harness for your trailer wiring, check it. It's down under the bed right near the rear bumper. Mine's wires pulled apart some, causing screwy tail/brake lights. The two connectors that plug into the T fit each other, at least on my 87 F250. I just unplugged both connectors from the T and plugged them into each other. Problem solved. I think in my case it was the tail running lights, but it's possible the brake wire could pull loose instead.
 

Cainon

Full Access Member
Joined
Sep 27, 2019
Posts
218
Reaction score
47
Location
Smithfield
Checked. Not that. The po hooked up a brake control and God only knows what else. There is so many wires going to absolutely nothing its unreal. It's a nightmare under here.
 

RetiringColt

Registered User
Joined
Mar 18, 2019
Posts
58
Reaction score
31
Location
Washougal WA.
Check the system like Franklin2 suggested. I would remove any add-ons done by previous owners. Also remove and repair damaged wires caused by scotch-lock type wire splices. they are a quick fix but break wire strands and introduce corrosion. In my experience I usually find the problem at a connector, the switch, or the load. Mine still worked but was really dim. I found corrosion at the round terminal between the bed and the rear fuel tank. hope this helps guys.
 

Cainon

Full Access Member
Joined
Sep 27, 2019
Posts
218
Reaction score
47
Location
Smithfield
Check the system like Franklin2 suggested. I would remove any add-ons done by previous owners. Also remove and repair damaged wires caused by scotch-lock type wire splices. they are a quick fix but break wire strands and introduce corrosion. In my experience I usually find the problem at a connector, the switch, or the load. Mine still worked but was really dim. I found corrosion at the round terminal between the bed and the rear fuel tank. hope this helps guys.

I have power getting to the hazard relay on the back side of the fuse panel but I here no clicking from the relay. Any ideas? It is brand new relay just bought it earlier this week
 

franklin2

Full Access Member
Joined
Feb 24, 2009
Posts
5,161
Reaction score
1,385
Location
Va
I have power getting to the hazard relay on the back side of the fuse panel but I here no clicking from the relay. Any ideas? It is brand new relay just bought it earlier this week

Those relays work on heat. The heat comes from the current draw of the bulbs. No bulb load it will not flash. Take the new flasher back out and make a jumper and jump the terminals out on the back of the fuse box where it plugs in. Then activate the emergency switch. All turn bulbs front and back should be on solid. If they are out or some are not working, that is why the flasher is not working.
 

Latest posts

Forum statistics

Threads
91,217
Posts
1,128,504
Members
24,045
Latest member
Ramtough01

Members online

Top