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2005 987 Boxster S - LED reverse Tail light flicker

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357 views 12 replies 6 participants last post by  Cayman S  
#1 ·
Subject line says it all - been using aftermarket LED tail lights for about 10 years. Think they're DRC style from memory.

I honestly don't know how long the problem has been happening, a neighbor mentioned it the other day!

It's only the left side assembly, and ONLY the white reverse lights.
Everything else works great.
I had a couple of spare canbus decoder units (long story), and I tried the problematic assembly with 3 separate canbus units and same problem each time.

I'm not sure if it has something to do with the rear backup camera I installed a while back, since that is activated when reverse is engaged?

I'm using one of those cheap Android head units that look identical to the factory had unit, with of course much more functionality.
I can't seem to find any way to disable the rear backup camera, and I honestly can't recall if I did anything special to set it up other than splice to the correct wire below the driver's seat?

Could this flickering be caused by the rear backup camera or is it likely to be either a simple case of a failing assembly or perhaps something to do with the main Porsche coding to provide the correct voltage for the LEDs since the car had the regular old school tail light assembly and I've never had Porsche or an independent 3rd party do anything to the car?

I'm afraid to waste nearly $1000 on a new set of LED tail lights if the problem wasn't the assembly and instead something like voltage?
And similarly have the dealer hit me with a large bill and find nothing!

It's a 20 year old car with 90K miles in terrific condition and it's really just used for nice days if I feel like going through some twisty roads!

Appreciate any advice, guidance (how to disable the rear backup camera without tearing up the wiring), and ideas on what is likely going on.

Cheers!
 
#2 ·
It’s always a good call to investigate the last place you completed repairs when searching for a new problem that could be related to the previous work. To me it sounds like a potentially loose ground, I’d recheck all the wiring. Myself? Before I took it to a repair shop, I would take the camera out of the loop and see if that restores function, even if that maneuver requires some cutting and re- soldering.
 
#3 ·
Rear cams are usually activated by the reverse switch, which then powers the camera. When the camera gets power, it provides a video signal to the HU (headunit) which is detected and switches to view it. The easiest way to disable it would be to unplug the RCA (or whatever connector if it's using) from the camera. Usually this would be somewhere near the rear camera, or just in the rear trunk or something, depending on how it was wired. Mine is an aftermarket, for example, and there are two connectors (RCA + barrel for power to the camera) which I tucked behind the bumper. The next connection for me was to the reverse power which I ran to the right rear assembly, which taps the reverse light wire.

Is the flicker visible to your eye, or are you seeing it in a camera view somewhere? Cameras will sometimes see flicker due to the shutter speed (which often varies depending on light available)... I see headlights flicker on some cars (most often Toyotas) in my dashcam, rear "mirror" cam on my other car, and even in my cellphone sometimes.
 
#4 · (Edited)
It's very visible to my eyes! The reverse LED's can go from completely off to super high frequency flicker, then everything in-between.
So, it's probably a wiring/power issue rather than ONLY the reverse LED lights failing?

Small update:
I disconnected the wiring to the rear camera (I remembered that all the connections were tucked in just behind the license plate), and even without the camera being connected the reverse light still flickers.
After reconnecting the camera power I opened the camera in the F-cam app while the car was in neutral (manual 6-speed) and there's no flicker and the camera seems to function normally.
So I guess the problem is where I had to splice into the correct wiring, which in my car turned out to be under the driver's seat near the rear control module?
I'm going to get to that next and unplug (I spliced using quick connectors with the spade plugs), and see if that resolves the flicker.
If it does then it's probably a grounding issue, if not would that likely point to an actual failure with the tail light assembly?
Or could it still be a problem with the head unit wiring?
Wish there was an easy way to completely disable the rear camera in the factory options for the head unit, just like there is for the front camera?
 
#5 ·
Since you state that you’ve been using these lights for 10 years with no problem, disconnecting the rear camera didn’t seem to be the cause of the problem, and this wiring has been in place and undisturbed under the drivers seat during this period, I would lean toward the taillight assembly failing. The LED lighting uses circuitry built into the unit which may have failed, causing this wonky operation.
 
#6 ·
Thanks.
So I just got to the black/blue wire that was under the driver's seat where I've used quick connects for the rear backup camera activation and removed the spade connector, while also have the camera disconnected and still getting the flicker.

There's no chance it bought still be some weird grounding issue? I'm not sure what else I can test?

I think I have the original OEM assembly, I suppose installing just the left side and testing the reverse light should tell me once and for all of its wiring or a failing LED assembly.
If the OEM assembly works then that should be definitive proof it's indeed the LED failure?

And then I guess probably smart to order some new tail lights....... The OEM assembly is so dated looking, and she's a good old girl and hasn't given me really any trouble over 20 years, so I'll treat her to some new dazzlers!
 
#7 ·
The OEM assembly works perfectly with the camera installed.
I should have probably checked that first, forgot I still had them in the attic!
So new lights it is, OR just switch out to the OEM assembly for my annual DMV inspection and save myself $1K+.
The chances of getting pulled over for one reverse light flickering are unlikely.
That might be the best plan, and maybe find a local electronics repair shop that might be able to fix the reverse light on the LED assembly!

You live and constantly learn!
 
#9 ·
The OEM assembly works perfectly with the camera installed.
I should have probably checked that first, forgot I still had them in the attic!
So new lights it is, OR just switch out to the OEM assembly for my annual DMV inspection and save myself $1K+.
The chances of getting pulled over for one reverse light flickering are unlikely.
That might be the best plan, and maybe find a local electronics repair shop that might be able to fix the reverse light on the LED assembly!
Agreed, I'd use the OEM for inspection, and then swap back. A flickering reverse isn't work $1k to me, at least. But then, I'm CHEAP.

Yes, you could see if you can have it repaired locally. If you have some electrical skill, you could test them on a bench power supply and see if they flicker there. If they don't, then it may just be a power fluctuation in the car... which you may be able to filter out externally to the assembly.
 
#8 · (Edited)
Does "DRC style" mean Del Rey Customs? If so, I just installed these on my car, and it's highly encouraging to hear you've been running them without any issues for close to a decade. These are sealed units, so it's hard to fix anything if they go bad. But damn, they look good!

Image
 
#11 ·
Yep, exact same. I think the brand is actually 'Jtec'.
Yeah they look fantastic, and I ran them every time I drove the car since I needed to turn the lights to the first position (not main xenon headlights for night driving) to power the aftermarket DRL light bar strip that replaced the fog light assemblies on the front bumper, plus matching white light LED bar side markers.
I'm bummed they went out, I'm going to find a local electronics repair shop (if they still exist!!) and see if they can repair so I can have a backup.
I thought about getting the same ones again since they're still for sale, but decided to go with something more updated looking but still very OEM looking.
 
#12 ·
It was highly irregular, going from super fast flickering to very slow and sometimes off for several seconds.

I tried using three separate canbus decoders that are attached to this style of aftermarket light, however, no joy.

I then unplugged/disconnected the wiring for the backup camera completely, both from the actual camera location on the back bumper, and where the power to the camera was spliced to the appropriate wire underneath my driver seat near the 'rear control module' box under the driver's seat. Still flickering the same.

Then turned off the backup camera functionality from the head unit - still flickered.

Since the backup camera wiring was in no way wired to the tail lights (which some installations require - I did follow one of the most detailed and followed installer guides for my specific head unit, actually here on Planet-9) and the Android head unit/camera did not require wiring/power/grounding from the tail light on my 6-speed manual car.

And finally (should have been the first thing to test in retrospect to rule out electrical issues), I installed the original OEM 'old school style bulb operated' tail light assembly on the problematic left side.
Reverse light did not flicker with the backup camera on and functioning. Also, the right side LED reverse light also worked perfectly without any flickering at all.
The original tail light assemblies look so awfully dated when comparing left and right sides!

Also, the flickering has been a more recent thing which after all the other trouble shooting probably points to failing electronics.

I've got new tail lights coming next week,