IS250 2012 - strange behavior of front DRLs

[ivansvk]

Hello guys,

I am looking for some help here regarding the really weird behavior of my front LED DRL on my 2012 IS 250. The headlights are stock from the factory, no mods or upgrades were done to the lights (or even the car, everything is stock) .

The thing is that when the headlights are turned on the original behavior of the DRL is that they slightly lower their brightness - until now everything is OK.

The issue is, that when I switch the right blinker on, both of the DRLs (left & right) fully light up and they're blinking along with the blinkers with the same frequency. It looks a little bit weird. Strange thing is, that this blinking is only for the right side blinker. When I switch on the left side blinker, the DRLs are working fine. This is when the headlights are turned on, or just the parking lights are turned on.

Here are the youtube videos of this issue, on both videos there are only the parking lights turned on to make this issue clearly visible. Apologize that there are two videos here for each side, I don't know how to cut the videos into one.

The first one is NOK - with the issue

RH blinker - NOK

The second one is OK - without the issue

LH blinker - OK

Do you guys have an idea what could be the cause of this? Has something like this happened to you? I have checked the bulbs, reset the ECU (by those two fuses) and also disconnected the Battery for a few minutes but without success.

Thank you in advance for your ideas and appreciate that.

 

[johnatg]

I'd check the earth connections for the headlights, particularly the right hand one.

When a light flashes when it shouldn't but in sympathy with another one, it is almost always due to a poor earth. eg you often see brake lights flashing with indicators - it's because the indicators are earthing through the brake lights. I think your situation might be similar.

I'm afraid I can't help with where the connections are and I don't have a wiring diagram showing DRLs - my IS250 was a 2005 model and my workshop manual is a bit old.

[Herbie]

I'd agree with John - check and clean up all the earths (grounds) for both light clusters. This is classic behaviour for a corroded or broken earth connection.

The factory where I served my apprenticeship had its own garage to look after the fleet of trucks and cars and I was in there one day fitting a couple of new mains sockets. While I was in there one of the skip trucks came in with the weirdest electrical fault I've ever seen.

Whenever the driver pressed the brake pedal the windscreen wipers came on, even though the wiper switch itself was off. That turned out to be a faulty earth somewhere because the wipers were getting a backfeed from the brake lights.

[ivansvk]

Thank you very much guys, I will try to find something suspicious like corrosion or broken cable behind the lights.

[ivansvk]

Hello everyone, little update regarding this issue.

Again thanks a lot to @Herbie and @johnatg for a really good tips. 

As I wrote, I have checked for anything suspicious behind the headlights. I have removed the airbox and I have found two corroded spots in this area - both are marked on the picture. One is ground for sure (1.), the second one probably too (2.), the second one is really corroded to be honest.

 

One of these is probably causing the issue, because I have brushed this spots little bit with little steel brush and then I have put a contact spray on these and the issue was gone for some time.

I have got a minimum time for this, so I will return for this at the weekend and try to clean these spots as much as I can.

Anyway, I want to replace this corroded part on this picture, just to be sure (and I want to have the car for the longest possible period 🙂 ) 

 

So, could you please advice me for what is the name of this part or how can I find this part somewhere? 

[johnatg]

I don't think you need to replace it (not sure what it is). Just take it off, give it a good wire brushing and paint it with some anti-corrosion paint (can you get Hammerite there?)

Spray the bolts with some wax (I'd use Waxoyl here in UK). Make sure there's no paint on the earth points, but spray the general area of the earths after you've reassembled.

[Herbie]

Again, John's beaten me to the answer but yes, I agree with everything he's said.

[ColinBarber]

18 hours ago, ivansvk said:

Anyway, I want to replace this corroded part on this picture, just to be sure (and I want to have the car for the longest possible period 🙂 ) 

This is a condenser. The bracket isn't available separately but doesn't have any grounding purpose, just a mechanical support.