Good afternoon.

 

This is an FYI for anyone who finds that the High Level Brake Light has totally failed (as I did in the pre-MoT check a few days ago) - Bare bones guidance only:

- Remove the two interior trim panels on the tailgate

- You now have access to the light fitting, and so unbolt from the tailgate (1 or more nylon nuts on threaded studs which are part of the fitting)

- Run a semi-sharp blade gently around the fitting, and push from the underside, until you can push it up and out of the tailgate - be careful not to damage either the 2-core cable to the fitting or the pipe to the washer (or, of course, the paintwork!)

- Carefully disconnect the plug on the 2-core cable from the fitting, and then the washer jet from the fitting - both have lugs on the sides which need to be gently released.

- If the Amber outer lens of the fitting has not already come away from the main body  (as mine did as I tried to get it out of the tailgate), then gently run a sharp blade around the edge until the two parts separate.

- You will now see the clear inner lens assembly over the LEDs on the Printed Circuit Board (PCB) - it is held in place by lugs/latches at both ends and 1/3 of the way from each end, so gently lever the lens up whilst releasing the lugs.  The PCB then simply unclips from the Lens.

- Near one end of the PCB, and on the other side to all the LEDS, there is a pair of metal pins - these are marked "+" and "-" on the track side of the PCB, and are the terminals for the 12V input to the LED assembly.

- Chances are that the soldered joints that attach them to the PCB are broken &/or corroded - so carefully clean the joints with a sharpish tool until you can see bright solder, and then reflow that solder with a small soldering iron whilst adding just a little more to make the soldered joints more secure.

 

Having done that, all 14 of the LEDS should then light up (as mine did) when fed with 12V to the two power input pins.! If they don't then you have probably got the supply polarity wrong and so switch the external leads.

 

Reassembly of the fitting is pretty much the reverse of taking it apart - probably the biggest issue is how to refit the outer lens to the main part of the fitting. Both items appear to be marked "PC" which I assume means "Polycarbonate". and a little googling indicated that you can use a wide range of adhesives, notably cyanoacrylates ("superglue") and expoxy resin, but I tried the solvent cement I use for joining PVC water pipes and it seemed to work (although I did have to clamp the parts together for a few minutes to let the adhesive set).

 

After that, it is a matter of  refitting the  plug on the 2-core cable to the pins of on the fitting and then the reinserting the washer jet (with its foam sealant ring!!) into its hole in the fitting, and then remounting that on the top edge of the tailgate - having added some sealant  to the edges before you finally push it into place - and finally  refitting the nylon nuts which pull it snugly down onto the body of the tailgate. Then you have the relative nightmare of getting the two parts of the tailgate trim back in place - I did that on my own because I had to, but I would strongly suggest that it is really a 2-man job!

 

PS: Don't know what the VAG price for the fitting is (dread to think) but the aftermarket part from ECP works out at around £34-£36 dependent on whether you order it off ebay, or through a branch and use a discount code. So, if you don't think you can repair your own fitting, then this is also roughly how to replace it with a new one.

 

Some pictures are attached - these were actually taken as I reassembled the fitting, but are shown (I hope) in roughly the order you see as you take it apart - and the 2 pins to be resoldered can be seen at the top edge of the PCB in the last shot, i.e. IMG023a.jpg

 

Edited 13 April, 20197 yr by jeallen01
Corrections & additions

Hi

 

Thanks for the detailed instructions. I have one failing LED in my brake light, so the plan is to attempt a repair, as I have some SMD LED's which are used in the back-lighting of LED TV's (50 for £3.00 from China).

 

Regards

 

 

Russ

Hi

 

I have now disassembled my brake light (being careful when removing the washer nozzle from the brake light!!).

 

I my case I have one slightly dim, but still still functioning LED and one that has failed.

 

They are arranged in 3 "blocks" connected in series with each block consisting of 4 LED's, making a total of 12 LED's.

 

The LED's are RED (not white as I had previously thought) and appear to be narrow viewing angle 30 degree, possibly these: Red LED

 

They are expensive to buy, due to the minimum order cost, but 5 can be obtained for £3 Here

 

I haven't ordered or confirmed that these are the correct LED's for the job, and it may be that all 12 need to be replaced to maintain an even illumination. If that is the case, it still works out cheaper at £9 for 15 (or less on an offer) than replacing the whole light, at £30 or more.

 

I will update once I have replaced the LED's

 

Russ

 

 

Have you resoldered the LEDs and associated track joins, could just be a bad join.

Hi Mac

 

I actually removed both bad LED’s and tested them with my multimeter and one was OK, so I refitted it, but it is slightly dim compared to the others. The other is definitely dead.

 

 Russ 

@russ17

If you still have the unit apart can you measure LED dimensions and voltage.

I have now completed the repair of the high level brake light, by replacing the two bad LED's and can confirm that these: https://www.ebay.co.uk/itm/152408458719 are a suitable replacement for the original LED's.

 

The original is on the left and the new one on the right (by the black X)

 

I manged to replace it using a standard fine tip soldering iron, which can be bought as a kit for about £11 https://www.ebay.co.uk/itm/Soldering-Iron-Kit-Electronics-Welding-Irons-Tool-Adjustable-Temperature-60W-UK/142927811015?epid=19035047006&hash=item21472951c7:g:c6sAAOSwDyldUQes.

 

May also be worth buying a multi meter as they are invaluable for fault finding on car electrical systems, and the diode test can be used to test the function of the LED's while still soldered to the PCB, without power. They LED's are are in 3 blocks pf 4 LED's, so when the meter is connected across any of the LED's, 4 will light dimly (assuming the polarity is correct), but if not correct, you wont damage them) , showing they are working. You can also check by connecting 12V DC on the two terminals of the PCB, which will show if all LED's are working.

 

The meter below has "auto range", so just set it to DC Volts and the meter will adjust the display to the appropriate range.

https://www.ebay.co.uk/itm/H01-Auto-Range-4000Counts-Digital-Multimeter-Backlight-AC-DC-Ammeter-Voltme/324331922925?hash=item4b83b065ed:g:~qUAAOSwJ7FfhDU~

 

I used some flexible adhesive like this: https://www.poundland.co.uk/19623-151-fantastic-elastic-glue/ for £1, and clamped the two halves together overnight. The glue also worked really well for sticking the door mirror glass on to the heated mirror pad!

 

Regards

 

Russ

 

 

Whilst I greatly appreciate the helpful information, it does seem to me that all that faff just to save £20 (ebay) or so isn't really worth it. You still have to take the tailgate internal panels to bits, so you might as well just fit a complete new brake light unit to get another ten years or so of service life.