No indication for not working bulb on the dash when remove any bulb from dome light units. There maybe be canbus connection, which doesn’t indicate not working bulbs, i don’t know that. Just sharing what I’ve found. And yes, this strip is not compatible with cars, it can be used at home, etc, even in cars, but is not certified by anyone. As i previously found, my car’s ceiling unist has three wires and double grounding
‘CANBus Compatible’ does not mean that it won’t glow dimly whenever the ignition is on - it might or might not. The important part of that notation is that the component will present a resistance to the power feed that indicates to the CANBus controller that it is there and is operational, so it will not cause a warning message on the dash. Some devices incorporate additional features that ensure smooth operation, but not triggering a warning is the essential bit.
If you install a compatible component in a place that does not require one, then the compatibility is irrelevant. However, that fitting might still be monitored, and the component might still glow dimly at times as it is scanned, even though a scanning failure does not trigger a warning.
Hi Ron, Jeff and all
My Car does not have any dash indication when a lamp fails, even a head light which has happened on a few occasions (usually low beam as this gets most use). I think all the dash indicators and alarms are more to do with the safe (not causing major damage) operation of the car mechanics, alternator , oil pressure and level, brakes etc. This type of failure could be reported in the fault log when the dealer (or someone with the right gear) scans the diagnostic system.
Yes I saw that. Possibly one ground is for the local manual switch which would be part of the dome light to turn it on manually when required, the other could be door operation which is probably activated by the car computer system. I would not be familiar enough with your make and model even if I knew this.
Yes Jeff I would agree with that. I am curious to know how fitting a low value resistor across the LED lamps to simulate an incandescent lamp would prevent them coming on if the voltage (CANBus??) was great enough. maybe there is a bit more trickery involved here. I am going to have a look at my car to-morrow with an oscilloscope to see just what this signal is. In fact this makes me interested enough to look deeper into this CANBus business to find out a bit more about the function of the system and how it goes about it’s business.
Ron. If this signal is only a low level just enough to activate the LEDs it may be possible to reduce it to below the LED active level just by inserting a diode in series with your LEDs. If this brings the voltage down to just below the LED threshold they should not turn on. This small drop should have no visible difference to the brightness when full voltage applied (dome light on). You would have to know just how much current the lLEDs require when full voltage applied to size the diode accordingly.
Will post what I find out to-morrow.
Cheers Bob
I think there is a misapprehension here. There is no CANBus at the interior light fitting - it is simply 12V and Ground. CANBus is the data network that conveys the information between network nodes, and there is no CANBus node in the lights (other than headlights in some high-end vehicles with comprehensive lighting control systems). In this case the CANBus information comes from the lighting controller (typically part of the part of the BCM) about the result of the scanning of the various lights. I guess the scanning is a resistance measurement (which would require a small voltage to be applied) but that is not part of CANBus and could well be different for different manufacturers, particularly for headlights where manufacturers have very specific standards. How that information is distributed and used is going to vary considerably amongst different vehicles. Whether or not it appears as a dashboard indicator probably depends on whether the display is LED symbols or a LCD/TFT.
Regarding possible battery issue, today I’ve checked that written on the screenshot is true - I left glovebox and trunk opened and their lights go off after 8 min
Tomorrow i will verify that the same is applied to the led strip
One question for connecting appear. Since i don’t want to mess and cut the wires, i plan to solder cable terminals to the relevant metal pieces on the ceiling unit. Do you think its a good idea? I’ve tried to make something quick with paint for better visualising
It’s unlikely you could solder terminals to the strip without seriously deforming the plastic underneath. Both the terminals and the strip will soak up the heat from the iron and transfer it to the plastic. Without knowing what the metal is it is difficult to predict how easily it would solder.
Usually the switch would be the best place to make the connection, such as a ‘Y’ harness to insert between the switch and the existing plug. However it appears from the image that the metal strips wrap around to become part of the switch mechanism, and there is no intermediate plug/socket. Is there room to do something similar at the connector shown in the image? The other option is the existing globe. For a tubular globe I have recovered the end caps from a broken globe, soldered to them, and inserted them over the ends of the installed globe with an increase in length that was within the available range of the spring fitting. A bayonet fitting would be more difficult. Of course, this assumes that the new light follows the switching of the existing dome, which might not be what you intend.
Is there an on-line group for your vehicle manufacturer? You may find someone who has already done soemthing similar.
Hi Jeff
Just how do you know this. As far as I can see Ron has not mentioned the make and model of his car.
It seems a hell of a coincidence that this LED strip is behaving EXACTLY the same as my retrofitted LED stop lamps. My dealer where I purchased my car (2008 Peugeot 307 station waggon type Diesel) and everywhere I have researched say the same thing. It is a CANBus signal, If it is not causing a problem ignore it. This is my case I can’t see it and it is NOT causing a problem.
Ron’s problem is this strip is going to be in the footwell and he will be able to see it, especially at night and it could be quite annoying. THAT is the problem.
A vehicle wiring diagram would be extremely helpful here but such things are very difficult to get hold of.
Cheers Bob
You know that there is no CANBus in the lights because there is no CANBus cable running to them. In some headlight assemblies there is the CANBus node as part of the assembly, so it is perhaps reasonable to say it is ‘in’ the lights. CANBus is not a signal impressed on the DC that is somehow making the lights shimmer or glow dimly. It is a transport mechanism that communicates between nodes and (with the exception mentioned above) there are no nodes in the light fittings.
The reason that you get similar behaviour across similar components in different makes of vehicle is that (1) there aren’t many different ways of implementing a particular solution and (2) components from the same supplier are often used across different brands and (3) component manufacturers usually try to make their products as generic as possible, to appeal to the largest range of customers.
Hi All.
Well I finally got around to tackling my car lights with an oscilloscope.
I did some measurements across one LED stop lamp.
Firstly I established that the lamp itself starts to glimmer at just over 6VDC.
Then I transferred attention to the car. The results were not exactly what I expected but I just assume Peugeot know what it is all about.
Firstly note that the 0V point has been moved down i division below centre, where that little blue arrow is
The first is with the ignition on and engine running and the LED fitted.
This seems to be a DC voltage of about 6.5 with about 0.5 sawtooth on top of it.
The second is with the engine off and key removed.
Note the sawtooth period has about doubled.
All this disappeared and trace returned to 0V about 60sec after ignition off and key removed.
Repeated with LED lamp removed from socket. Same result.
I don’t quite know what to make of all this. I suppose Peugeot knows as everything seems to work OK. For interest I will have to dive a bit deeper when I get a bit of time but for the moment it is what it is.
This does not help you Ron. The only thing I could suggest is you investigate exactly hat is happening across your lamp to see if it is similar. A bit difficult if you don’t have access to an oscilloscope but noting the DC present on my system you might get some idea with a multimeter. If the system is similar you might measure some volts.
If it is similar I have a suggestion which might work.
Change your strip from 12V to 5V. fit an 8v2 zener diode in series with the strip. That way anything below 8v2 will be ignored. Your car battery should be well over 12V so you will still get nearly 5V across the strip. Those LEDs might be pretty bright so you might even be able to use a 9v1 zener. Depends on how bright you want the LEDs.
To try this the zener will have to be rated for the current the strip needs. You have not indicated what that is.
Another alternative is to devise a circuit that will sense when the volts gets near to 12V and arrange to switch the LEDs at the chosen condition. That could get a bit messy and exotic.
Afraid that is all I can think of at the moment mostly due to my lack of knowledge regarding this sensing system and the phantom 6V or so that appears until the whole system shuts down which seems to be about 60Sec after switch off and key removal.
Cheers Bob
If soldering is dangerous, i can insert wires in the connector, then insert the connector in the ceiling unit. In the forums i saw different ways to wiring - soldering to the wires in the fuse box, anywhere else in the wires, soldering to the both ends of the bulb
I’ve double checked today, unfortunately led strip doesn’t go off after 8 minutes, in contrast with the other lights. So you’re right it may look weird when it can’t stop shining under the steering and glovebox all the time when my car is parked(at night). Will consider if it’s worth it. My car is fiat bravo 2007, similar platform to Peugeot. Am I understand correctly that your stop light never goes completely off 
Hi Ron
No. It does go off about 60sec after the ignition is off, key removed and door closed.
While something is happening like engine running, door opened etc the light is faintly glimmering. It goes off when everything shuts down by the computer system.
I was thinking it might be more of a nuisance while driving.
If it is like mine it should go out after you take the key out and shut all doors. 60Sec is quite long when you are waiting so be patient.
If you open a door or anything the sequence will start again.
I did neglect to have a look across an incandescent globe. Maybe do that today or to-morrow if time permits. A bit of a pain to get at.
Cheers Bob
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Please note: I am not a car person so this is just a thought (and I know cars electronics don’t always work the way I think about things… so this could be way off.
If the LEDs stay glowing for a while, all the time, is the Voltage Low when dim or is it more a PWM with a low “on” period e.g. 12V always present but switch to ground to allow current to flow?
The reason I ask, if the actual voltage is low (on the +12 V side), could you add a switch/relay that wont “trigger” until the voltage is high enough ?
Note: Im assuming you want the LED strips to come on when the interior light comes on and go off when it goes off? … so an On event with a timer for off wont work.
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Okay, 60 seconds is nothing. Today i realized that testing inside the car in unlocked car. So changed the tactic. Connected led strip where it should be connected, verified its on for ~30 seconds when door is opened, then goes “off”. This how it looks when it’s not completely off. Quite bright at night, yea
Then left the car and lock it. After 9 minutes it goes completely off. I found that other car users are complaining the same, the reason is that there is some electricity in the connector enough to light partially this led strip but not a normal bulb. So, I think everything will be okay with my battery
Edit - also found some people complaining that led bulbs in their homes doesn’t go completely off. But not for 60 seconds or 9 mins, forever until the switch is pressed. The describeb reason was the switch
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This is a common problem and is due to the lack of a bleed resistor across the AC input to the power adapter built into the lamp. It is not relevant to a similar problem in the 12V DC system of a motor vehicle.
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Update - installation is done. Took me 5 hours in the weekend and still not completely finished(cables needs to be hidden). I made mistake initially buying red and black wires separately, instead of both wires to be packed in a protective sleeve. Led strips were also the cheapest. Several issues appeared - wires not exactly 5 meters and almost got short. I placed them in the left a pilar, where already got camera cables and maybe should used the right a pilar. One wire of the led strip broke at the end and frustrated me because its very difficult to solder in car, without any facilities. But I fix it and everything worked as during testing. Connected the wires in the ambient light connector, then inserted ambient light panel. It’s good to have more light in the evenings. Sorry that didn’t take any pictures during work, but was very cold and actually was nothing interesting - just measuring, soldering and moving wires from home to the car and back. Will upload pictures of the lighting when wires are hidden
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I’m adding pictures with the final result. I think i looks pretty good. Wires soldered to the led strip are very thin and one of them needed re soldering
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Hi @Ron280737
Glad to hear that you managed to get it all working!
