LED brake light is DIM

T5R92011 · Nov 2nd, 2018, 19:25

It was pointed out to me that my passenger side brake light wasn't working.

Checked it out and discovered that A) These facelift cars have LED brake lights all round and B) I wiggled the connector a bit (with brake pedal wedged down) and the brake light came on, albeit rather dim (all individual LEDs were at same brightness level) compared to the other two brake lights.

I'm going to try cleaning the contacts but has anyone else experienced this?

Am I going to need a new LED unit?

andy_d · Nov 2nd, 2018, 20:48

give the connectors a Good clean first, esp the gnd ones

T5R92011 · Nov 2nd, 2018, 21:35

Tried cleaning the contacts with MAF sensor cleaner and also tried to clean up the circuit board (which cannot be removed unless you heat up the glue and separate the unit) to release the circuit board...at least thats how it looks. I didn't try forcing anything.

For a brief moment the brake light returned to full brightness, but then soon went back to DIM.

The reason for iffy electronics is stamped on the back of the unit.

Why the hell did this car need LED brake lights???

andy_d · Nov 2nd, 2018, 21:54

reflow the solder pads,worth a punt

Missing Lincs · Nov 3rd, 2018, 08:14

If you have a multimeter you could measure the voltage at the brake light connector coming from the car. Compare the left and right side, if they are the same then its likely that you fault is within the brake the brake light unit. If the left is lower then it points to a problem further back in the wiring.

Alternatively try swapping the brake lights over, I know they won't fit but if the connectors are the same you could plug them in and see if it's the lamp unit or the car wiring.

Clan · Nov 3rd, 2018, 10:30

Quote:

Originally Posted by T5R92011

It was pointed out to me that my passenger side brake light wasn't working.

Checked it out and discovered that A) These facelift cars have LED brake lights all round and B) I wiggled the connector a bit (with brake pedal wedged down) and the brake light came on, albeit rather dim (all individual LEDs were at same brightness level) compared to the other two brake lights.

I'm going to try cleaning the contacts but has anyone else experienced this?

Am I going to need a new LED unit?

The problem with LED is not the LED's themselves but the micro controllers on the circuit boards in the light , any moisture at all will kill them ...

maartenr · Nov 5th, 2018, 12:29

perhaps you could messure resistance on both sides and compare?

T5R92011 · Nov 6th, 2018, 17:06

Here is the FIX...

Appears to be easier to fix on the V50 due to different layout of the brake lights.

I'll need to double check whether I can get the circuit board out of the S40's taillight assembly.. it looked to big to pull out of the gap shown in the picture, but I'll double check anyway.

+ YouTube Video

Nov 2nd, 2018, 19:25	#1
T5R92011 FCW Auto Service Last Online: Yesterday 20:11 Join Date: Feb 2015 Location: Gloucester	LED brake light is DIM It was pointed out to me that my passenger side brake light wasn't working. Checked it out and discovered that A) These facelift cars have LED brake lights all round and B) I wiggled the connector a bit (with brake pedal wedged down) and the brake light came on, albeit rather dim (all individual LEDs were at same brightness level) compared to the other two brake lights. I'm going to try cleaning the contacts but has anyone else experienced this? Am I going to need a new LED unit? __________________ FCW Auto Service (Gloucester) https://www.fcw-autoservice.com

Nov 2nd, 2018, 20:48	#2
andy_d Premier Member Last Online: Apr 24th, 2024 21:26 Join Date: Aug 2009 Location: birmingham	give the connectors a Good clean first, esp the gnd ones __________________ 940s - 2l / 92 < gone&missed s401.8 xs auto <gone >V50 2.4SE Geartronic aka "the new money pit" "skyship007 has now been successfully added to your ignore list. "."

Nov 2nd, 2018, 21:35	#3
T5R92011 FCW Auto Service Last Online: Yesterday 20:11 Join Date: Feb 2015 Location: Gloucester	Tried cleaning the contacts with MAF sensor cleaner and also tried to clean up the circuit board (which cannot be removed unless you heat up the glue and separate the unit) to release the circuit board...at least thats how it looks. I didn't try forcing anything. For a brief moment the brake light returned to full brightness, but then soon went back to DIM. The reason for iffy electronics is stamped on the back of the unit. Why the hell did this car need LED brake lights??? __________________ FCW Auto Service (Gloucester) https://www.fcw-autoservice.com Last edited by T5R92011; Nov 2nd, 2018 at 21:39.

Nov 2nd, 2018, 21:54	#4
andy_d Premier Member Last Online: Apr 24th, 2024 21:26 Join Date: Aug 2009 Location: birmingham	reflow the solder pads,worth a punt __________________ 940s - 2l / 92 < gone&missed s401.8 xs auto <gone >V50 2.4SE Geartronic aka "the new money pit" "skyship007 has now been successfully added to your ignore list. "."

Nov 3rd, 2018, 08:14	#5
Missing Lincs Premier Member Last Online: Yesterday 08:37 Join Date: Jan 2010 Location: Louth	If you have a multimeter you could measure the voltage at the brake light connector coming from the car. Compare the left and right side, if they are the same then its likely that you fault is within the brake the brake light unit. If the left is lower then it points to a problem further back in the wiring. Alternatively try swapping the brake lights over, I know they won't fit but if the connectors are the same you could plug them in and see if it's the lamp unit or the car wiring.

Nov 5th, 2018, 12:29	#7
maartenr New Member Last Online: Feb 10th, 2021 11:14 Join Date: Oct 2018 Location: Frankfurt	perhaps you could messure resistance on both sides and compare?

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