puddle light not like LED Topic is solved

Post by **darrylrobert** » 21 Mar 2020, 03:10

I bought some Osram LED globes for my 'puddle lights', fitted on the passenger side and they work well. However when i fitted to drivers side the LEDflashed for 1 second then went off. Thinking that the LED died i checked using a test battery and it illuminated. Tried putting it back reversing polarity but nothing, put the incandescent back in and it worked..so checked the connector looks clean and LED contacts pins look okay.

I checked with my scantool and it confirms 'Light inactive'

Will try swapping the LEDs tomorrow or using a different LED.

Something to do with Canbus?.. maybe i need to add some load to the curcuit?

: 2008 puddle light

Post by **oragex** » 21 Mar 2020, 04:35

I don't think there's Canbus for these. I've used regular cheap chinese LEDs
Inside the car it's a different story, some dome lights don't like LEDs, and most cheap LEDs on the DIM (01-03) are too weak and fail very soon.

Post by **darrylrobert** » 21 Mar 2020, 05:58

Nice video thanks, yes i have a few fault codes after installing LEDs in my interior dome lights but they work great and what a major improvement.

I will probably install the incandescent bulb in the spare socket (hole) thats behind the mirror and the LED in parallel, this 'should' work.

Is this a bulb hole behind the mirror for blinker?

: Bulb hole behind mirror; hole in mirror.jpg (46.87 KiB) Viewed 3498 times

Post by **jimmy57** » 21 Mar 2020, 10:06

CAN isn't the problem, it is the transistor circuit operating the light. Since it works on LH side that makes me think the bulb you used on RH has an issue. I have LED'd several Volvos and BMWs and I have had to try different bulbs several times before finding ones compatible with the circuit. Some LEDs use resistors to regulate voltage to LED level and some use a pulsing circuit. Some of either type will work. I can't tell you brands as I have bought bulbs again from same supplier only to find the next order will not work. Even when they work a scan may reveal codes in CEM, REM, and UEM and others. You also will find that some will glow at night when not on and will glow until the modules go down minutes after you leave the vehicle. The incandescent bulbs would not light with the diagnostic check voltage but LEDs will. It actually is a nice feature as it mimics the ambient lighting they added to new models.

Post by **chrism** » 21 Mar 2020, 10:18

I converted the instrument lighting in 1800 to LEDs. I found the bulbs to be polarity sensitive. If I put them in one way they wouldn’t work. Turning them in socket got them working.

Post by **volvolugnut** » 21 Mar 2020, 11:15

LEDs are Light Emitting Diodes. Diodes are polarity sensitive - there only work one way. If they do not have built in current protection, installing them backwards, may cause them to burn out.
volvolugnut

Post by **jimmy57** » 21 Mar 2020, 12:14

I have bought many LED drop in replacement bulbs that are not polarity sensitive. I think most any of the major brands like Philips, Osram, etc. that cost more have the dual polarity support circuit. I have bought some very good bright ones for under a $1 each that were polarity sensitive but also didn't fail if installed reversed. They were not marked in any way so you could readily know which polarity to orient them to.

Post by **chrism** » 21 Mar 2020, 15:37

jimmy57 wrote: 21 Mar 2020, 12:14 ....I have bought some very good bright ones for under a $1 each that were polarity sensitive but also didn't fail if installed reversed. They were not marked in any way so you could readily know which polarity to orient them to.

My experience exactly. Once I discovered the problem I went through and bench tested all of them to determine + and - and marked the bases with red and black Sharpie.
As a side note, I also found I couldn’t “ground” them all to earth like the old incandescent bulbs - had to daisy chain a new negative path back to the special LED dimmer.