Brake Lights Not Working

Reedrombo

New member
My brake lights are out, but the tail lights work, so the bulbs are fine. I changed the brake pedal switch, still nothing. So I'm assuming there's a wiring issue between the pedal switch and the lights. Anyone have any suggestions for places to check first before I start tracing wiring back?
 

jmoller99

Own a DAD ODB2 Unit.
I had a problem on one side with corrosion on the light holder at the rear (it's galvanized steel strips held in place by plastic assemblies). I tried soldering the bad connections and eventually just bought replacements parts.

Get a volt meter and check if the voltage is getting to the connector.

WARNING: Use USA Parts in the USA. I originally bought a set of European tail lights with new light holders. Its wired differently (and of no use to me in the USA). The Euro tail lights look and work fine.
 

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Reedrombo

New member
The taillight functionality of that bulb and housing work though. The brake light and tail light are the same light. Pressing the brakes triggers the taillights to become brighter. That function isn't working so it has to be wiring somewhere between the pedal switch and where the wiring forks to the rear lights
 

ECU

2006 T1n 118 Sprinter
The bulbs have two filaments. So the brake portion of the lights can be burned out and the tail light portions still work.
Start at the tail lights. Check the bulbs. The holder can get corroded and cause the electricity to not flow to the brake light filaments. Third thing to check would be the fuses. Fourth thing is to replace the switch. (You've done that)
 
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Reedrombo

New member
I tried new Bulbs first obviously. That didn't work so I checked fuse next obviously, that was fine. So then I changed the brake pedal switch. That didn't work. So now I'm asking about wiring. Any advice there?

Thanks guys.
 

Cheyenne

UK 2004 T1N 313CDi
If you unplug the tail light from the harness do you get voltage at the plug when someone presses the pedal?

If not try unplugging both tail lights AND disconnecting the high level stop lamp (assuming you have one).

Keith.
 

bigvic0007

New member
Anybody find a solution? I’m having the same issue with my van. Going to get my volt meeter and hunt down the problem today
 
One of the first problems I had to solve when I bought my Sprinter (2003 OM612) was with the brake lights/tail lights/turn signals. After light bulbs, brake light switch, fuses, changing both tail light circuit boards fixed all the issues. Mine had pretty much sat for a year, according to the previous owner. My high mount brake light does not work.
 

fhuang1

New member
I temporally fix break light by add a cap I found, so I can go home. I don’t like light fixture as well. They are quite cheap and surprisingly holding up so well.
 

220629

Well-known member
For future members looking in on this thread.

There is quite a bit of information about the T1N tail light assemblies in this thread. Clicking links within the thread will provide more insight.


vic
 

fhuang1

New member
Thanks, this is the most confusing part of manual. I got it, but I still don’t know whether it is flasher problem. Maybe it gets some signal from comb switches, such as some power to the flasher. I short the relay power, so it l can lights up the emergency light, but no clicking. I can manually turn on off the left or right turn signal by hand with left or right turn signal. The reason I did all these, I don’t know which went bad, comb switches or the fuse box under wheel, or maybe flasher circuit inside the fuse box. I am really confused now.
 

fhuang1

New member
Because, none of the service wiring shows, turn signal/washer/ wiring, then I have not seen any one service these two.
 

fhuang1

New member
C1 of the fuse box r really not helpful, I provide power and ground to flasher, try to see waveform, however, it only shows a constant voltage, no waveform. It could be not sensing current of lamp, disable the flasher. it does has pin 4 output, but a constant high.
 

fhuang1

New member
At one point, I litter.y see the turn dies with emergency button pressed down, the turn flash for a few seconds, then totally dies.
 

fhuang1

New member
I still more inclined to say flasher ic went bad, as it dies gradually, or the lamp sensing, since my brake stucked on, it 26w.
 

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