Brake lights stay on

is the driver left side as in USA? (LHD or RHD)?
educated means too we read the service manual (SM)
and the page on rear lamps. Schematics, or we just fiddle about and guess.
https://eautorepair.net/Marketing/Default.asp


fuses all good, we check them all.
the problem #1 is on BCM cars, no 2 BCM work the same
so again the SM comes to our rescue.
BCM is body brain and runs all lamp, in odd ways, you don't know yet.
answering for only USA cars, LHD.
brake lamps are rear amps 2 or 3 total

that socket burnup (where) is signs of dead shorted lamp.
needs new lamp first and new socket 2nd.
the IPS runs all 3 rear stop lamps left, center and right.
facts, Schematic on my screen
all 3 lamps use the same single wire to glow. branks
but not ground
left uses GF04 ground wire to body.
GF04 ground runs the other 2 lamps.
so the only failure here is left lamp

• the lamp bad
• the wire bad (or socket0
• or the ground bad GF04

2 man job, step brake, 2nd man meter in hand.
a voltmeter tells you which one is bad.
step on brake pedal 12vdc here, all 3 on that 1 wire.
ground reads 0v.
yes ,yes, then lamp is bad.


meter black test wire must be to perfect metal ground for tests.
max ground volts is 0.5vdc max.but 0 is goal.
the lamp shorted I guess and burned up parts related.

The ground wiring on newer vehicles is a little complicated. Older cars, the ground would have been to the body around the tail-lights, but these have a ground wire in the harness and is connected to the turn-signal switch, and other sources. I don't think you have a ground problem. Does the fuse blow as soon as you press it into the fuse-block, or when you step on the brake? I believe you have a dead short somewhere, possibly a pinched turn-signal wire close to the tail-light assembly. Brake lights work through the turn-signal wires from the turn-signal switch on the steering column. That's how you can have one side blinking for turn while the other side stays on for brake. I'm kind of shooting in the dark here because I don't know what all you've done. If you replaced the turn-signal switch in the steering column, you may have pinched a wire or something there. Another thing, if the fuse doesn't blow as soon as you press it in, will both turn-signals work as long as you don't press on the brake? If you can provide a little more information, I might be able to help you more. One last thing....Have you replaced tail-light/turn-signal bulbs? If so, be sure you used the right bulb. You should only have two bulbs, one for back-up lights and one 1157-type combination for tail-lights and turn-signals. I have seen people use a single contact (1056) bulb in place of a 1157, which creates a short from brake/turn-signal back into the tail-light circuit. I do have a 1994 Dodge Dakota.

is that volts with the plug connected sounds like either a ground at lites or brake lite switch under dash, try making your own ground
at tailite, wayne

Stop Lamp Circuit Description
The STOP HAZ fuse in the IP junction block supplies battery positive voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close and battery positive voltage is supplied to the center mounted stop lamp (CHMSL) and both left and right stop lamp assemblies. The left stop lamp is grounded at G304 and the right stop lamp is grounded at G304.

Check the ground ! Testing an not guessing is the way to find the problem . Do you know how to test automotive electrical systems an circuits using a DVOM - digital volt ohm meter ? How to use an read a wiring diagram to pin point testing areas in a wiring harness ?
Basic Electricity for Service Techs Ohm law Current Flow Opens Shorts
How to Use Multimeter to Troubleshoot Common Problems
Mastering Voltage Drop Testing with Pete Meier and Jerry Truglia

Stop Lamps Inoperative
Step
Action
Yes
No

2
Inspect the 20 Amp STOP HAZ fuse.
Is the STOP HAZ fuse open?
YES - Go to Step 11
NO - Go to Step 3
3
Use a test lamp in order to backprobe connector C1 of the brake switch connector between terminal A and ground. Refer to Circuit Testing in Wiring Systems.
Does the test lamp light?
YES - Go to Step 4
NO - Go to Step 5
4
With the brake switch closed, Test for positive battery voltage at terminal B of connector C1. Refer to Circuit Testing in Wiring Systems.
Is voltage present?
YES - Go to Step 6
NO - Go to Step 7
5
Repair the open or short to ground in the Fuse Output-Battery between the fuse block and the brake switch. Refer to Wiring Repairs in Wiring Systems.
Is the repair complete?
YES - System OK
--
6
Use a test lamp in order to backprobe the turn/hazard headlamp switch assembly connector C2 terminal A and ground.
Depress the brake pedal.
Does the test lamp light?
YES - Go to Step 8
NO - Go to Step 9
7
Inspect the adjustment of the brake switch. If the adjustment is correct, replace the brake switch.
Is the repair complete?
YES - System OK
--
8
Replace the turn/hazard headlamp switch assembly.
Is the repair complete?
System OK
--
9
Repair the open in Stop Lamp Switch Output between the brake switch and the turn/hazard headlamp switch assembly. Refer to Wiring Repairs in Wiring Systems.
Is the repair complete?
System OK
--
10
With brake switch open test terminal A of the brake switch for continuity to ground. Refer to Circuit Testing in Wiring Systems.
Is ground present?
YES - Go to Step 11
NO - Go to Step 12
11
Repair short to ground in Fuse Output-Battery Circuit. Refer to Wiring Repairs in Wiring Systems.
Is repair complete?
System OK
--
12
Test the Stop Lamp Switch Output Circuit for continuity to ground. Refer to Circuit Testing in Wiring Systems.
Is ground present?
YES - Go to Step 13
NO - Go to Step 14
13
Repair short to ground in the Stop Lamp Switch Output Circuit. Refer to Wiring Repairs in Wiring Systems.
Is repair complete?
System OK
--
14
Test terminals F,G,B and C on the Hazard Warning Switch for continuity to ground. Refer to Circuit Testing in Wiring Systems.
Is ground present?
Go to Step 15
--
15
Repair short to ground in suspect CKT. Refer to Wiring Repairs in Wiring Systems.
Is repair complete?
System OK
--

u have a short loose ground or power wire check all bulb sockets ur head light switch can be bad also

To Track down the problem you need to disconnect the Battery and use a Multimeter set to OHMS.

You are grounding somewhere. Start with the Brake switch and see if it is grounded. Then take off the wires to the switch. Check the wires going to the switch and coming from the switch. One side has to be the problem. Check with a parts place like Autozone or Oreillys for a Brake relay in the power box. If the power wire is grounded unplug the Brake relay and see if it drops the connection.

If it is a wire problem, keep tracing the grounded wire until you find a connection you can unplug to make the Ohmmeter drop. Remember the overhead Brake light on the roof. You may have just worked on the Taillights. The bad wire may be grounding in the roof or on the frame.

Once you isolate the bad wire you may want to run a new one.

In order of probability......
1,brake light bulbs.
2,brake light switch (above your foot when placed on brake pedal).
3,brake light fuse.

I've had a similar problem is so matter what i do the lights would stay on dim. My solution to my problem was that I had a bad/loose ground.

To your problem with the high mount break mount staying on is that you have a loose ground or a tear in the wire.

but since your truck isn't really that old I would first try contacting the Ford dealership asking them if there was a certain recall on this problem of somesort

Troubleshooting Procedures - Read Completely Before Beginning
(American Car) All Brake Lights Not Working

• Check System Fuse: A fuse is used to protect the brake light circuit from amperage overload. If the fuse has failed it will not allow the electrical current to continue to the brake lights. To check the fuse, first locate the brake light system fuse in the fuse panel which is either under the dash or under the hood in the power distribution center. Connect the test light to a ground like an engine or dash bracket and turn the ignition key to the "on" position. Using the test light probe both sides of the fuse. If the test light illuminates on both sides the fuse is ok continue onto the next step. If one side of the fuse illuminates the fuse has failed and needs to be replaced. If the fuse fails as soon as it is replaced or when you apply the brake pedal the brake light electrical circuit is shorted to ground. Rarely a system short can occur, a car repair manual is needed to find the wiring schematic for the brake light circuit. Once the brake light wiring has been located inspect and repair as needed.
  
• Check Brake Light Bulbs: All cars have three brake light bulbs that create the brake light illumination affect. If all of these brake light bulbs fail no brake light operation will occur. I know what you're thinking, you might say all three brake lights at once? But in reality one brake light went out at a time and you did not notice. People only tend to notice something when they almost run into the back of your car to help persuade them to inform you the brake lights aren't working. Remove any of the brake light bulbs to confirm the bulb is ok or burned. After the bulb has been removed inspect the filament and replace if failed. If the brake light bulbs are ok continue to the next step.
  
• Checking the Brake Light Switch: A control switch is used to connect the brake light electrical circuit. This switch is located near the brake pedal lever. Basic switches have just two wires, power in and power out to the turn signal switch. Use a test light that is grounded and with the key in the "on" position test for power at one side (wire) of the switch, then press the brake pedal while testing the opposite side (wire). It should illuminate the test light, if electrical power is connected through the switch go to the next step. If no power is detected through the switch the brake light switch has failed and replacement is required. If your car is equipped with more than two wires integrated into the brake light switch a car repair manual is needed to locate the proper brake light circuit wiring.

you need to follow the ground wire for that socket... most likely two ground wires... unscrew it from the frame and clean it up so it makes a better contact... reattach it and should be good to go.

Robert

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