Indicator Bulb illuminates as sidelight (dipped headlight)

[kom458]

So I have an sidelight out and the indicator bulb comes on, I know this is a thing they did for some reason but I can't seem to get rid of it. I have changed the bulb for the dipped headlight and it is still doing the same. I had the whole bumper off doing some other work so I figured I'd plug the light into the other side and see if it worked, it did! The sidelight lit up no problem plugged into other side! So it's not the headlight unit, it's something within the car itself, I'm guessing wiring or a module?

Does anyone have any ideas at all? I'd be so grateful!


EDIT:
Forgot to say, I had a look at the wiring and although part of the protection tape had worn a little near the wheel arch, I couldn't see any damage to the wiring itself

 

[enuff_zed]

Are you sure it's not the sidelight bulb rather than dipped beam? Have you tried changing that?

Oh, and welcome to the forum.

 

[kom458]

Are you sure it's not the sidelight bulb rather than dipped beam? Have you tried changing that?

Yes checked and double checked. plugged the whole unit into the other side and it worked without a problem, sidelight turned straight on when it was plugged into other side

Thank you! Long-time lurker, first time poster!

 

[enuff_zed]

Are you sure it's not the sidelight bulb rather than dipped beam? Have you tried changing that?

Yes checked and double checked. plugged the whole unit into the other side and it worked without a problem, sidelight turned straight on when it was plugged into other side

Thank you! Long-time lurker, first time poster!

Hmmm. And it definitely started when the bulb failed? I wonder if you have a dodgy connector on that side?
The other thing that springs to mind is that I had a 2.5si a while back with a similar issue, but in that case it was both indicators lighting up.
The seller told me this and proved it was an internal fault with the LCM.
In this case it was possible to fit another LCM which cured the issue but left a tamper dot on the instrument cluster which I'm told isn't easy to remove.
I sold the car later to someone who actually liked the front indicators being lit (US-style) so I kept the other LCM.
I stand to be corrected but I believe there are two indicator bulbs per side? Only the inner one lights with that fault, so it should still work as an indicator with the other bulb.
Whereabouts are you?
Could maybe see if anyone could lend you another LCM to slave in, just to rule that out?

 

[kom458]

Hmmm. And it definitely started when the bulb failed? I wonder if you have a dodgy connector on that side?
The other thing that springs to mind is that I had a 2.5si a while back with a similar issue, but in that case it was both indicators lighting up.
The seller told me this and proved it was an internal fault with the LCM.
In this case it was possible to fit another LCM which cured the issue but left a tamper dot on the instrument cluster which I'm told isn't easy to remove.
I sold the car later to someone who actually liked the front indicators being lit (US-style) so I kept the other LCM.
I stand to be corrected but I believe there are two indicator bulbs per side? Only the inner one lights with that fault, so it should still work as an indicator with the other bulb.
Whereabouts are you?
Could maybe see if anyone could lend you another LCM to slave in, just to rule that out?

Hmm okay that's interesting. When I bought the car, they were both like it so I don't really know about when it started. I never thought much of it as I never use the dipped lights, it was only when I came to MOT and they failed the car for it that I started looking into I and I changed both bulbs as I read that was usually the problem, the left-side started working fine but right-side didn't

Yes I believe there are two, it looks like there's two bulbs lit in there. The indicator works fine when I need it.

I'm in Wolverhampton, West Midlands

 

[enuff_zed]

Bit far for me to pop round
Go back to basics then.
Are you sure the bulb fitted in that dipped beam is definitely a good one? Are you sure it is correctly connected?
Sorry if you've done all this, but having been the victim of a new bulb that was duff, it can lead you way down the wrong track.

 

[kom458]

Bit far for me to pop round
Go back to basics then.
Are you sure the bulb fitted in that dipped beam is definitely a good one? Are you sure it is correctly connected?
Sorry if you've done all this, but having been the victim of a new bulb that was duff, it can lead you way down the wrong track.

aha shame! How much is an LCM?

Yes definitely a good bulb. I had the bumper off doing some other work so I pugged the entire light into the other side of the car (really hoping it wouldn't work as then I knew it was the light itself), but it worked absolutely fine so I know the bulb is good and so is the light itself

 

[enuff_zed]

aha shame! How much is an LCM?

I believe around £25 + postage is an accepted figure amongst the forum members who break them?
But do consider I may be completely wrong with my diagnosis though.
Worth waiting for a few more inputs before you jump as you will get that tamper dot if you swap it.

 

[kom458]

aha shame! How much is an LCM?

I believe around £25 + postage is an accepted figure amongst the forum members who break them?
But do consider I may be completely wrong with my diagnosis though.
Worth waiting for a few more inputs before you jump as you will get that tamper dot if you swap it.

That's not too bad. For the sake of ruling it out, I might just buy one.
No I appreciate the input! I am just really confused by it!

Just a quickie, you said the guy who bought your old car with that liked it, is it legal to use those lights as sidelights? Just thinking cause that failed the MOT but if others use them, maybe it was wrong? Don't suppose you know?

 

[enuff_zed]

Just a quickie, you said the guy who bought your old car with that liked it, is it legal to use those lights as sidelights? Just thinking cause that failed the MOT but if others use them, maybe it was wrong? Don't suppose you know?

I wonder if that's because it was just one on so could be mistaken for indicating?

 

[kom458]

Just a quickie, you said the guy who bought your old car with that liked it, is it legal to use those lights as sidelights? Just thinking cause that failed the MOT but if others use them, maybe it was wrong? Don't suppose you know?

I wonder if that's because it was just one on so could be mistaken for indicating?

When it was sent through MOT, it had both sides like it

 

[enuff_zed]

Just a quickie, you said the guy who bought your old car with that liked it, is it legal to use those lights as sidelights? Just thinking cause that failed the MOT but if others use them, maybe it was wrong? Don't suppose you know?

I wonder if that's because it was just one on so could be mistaken for indicating?

When it was sent through MOT, it had both sides like it

Really? That's my theory shot down then.

 

[enuff_zed]

Bit far for me to pop round
Go back to basics then.
Are you sure the bulb fitted in that dipped beam is definitely a good one? Are you sure it is correctly connected?
Sorry if you've done all this, but having been the victim of a new bulb that was duff, it can lead you way down the wrong track.

aha shame! How much is an LCM?

Yes definitely a good bulb. I had the bumper off doing some other work so I pugged the entire light into the other side of the car (really hoping it wouldn't work as then I knew it was the light itself), but it worked absolutely fine so I know the bulb is good and so is the light itself

Just a thought, did you plug the known good unit into the duff side, to see if the fault occurred on that one?
That would point more towards the LCM then I'd have thought?

 

[colb]

Sounds strange, usually if a bulbs out you will get a dash warning light and the indicator bulb on the failed side will turn on to act as a sidelight backup. Have you checked the rear lights for a bulb out in case thats the cause?
Another check would be to scan the car and see if the bulb warning function has been coded out on the car. This can be done using BMW Scanner 1.4 on a laptop, coded my sidelight warning out after fitting led bulbs because although being sold as Canbus error free they wern't when fitted to my Z4 and lit the bulb out warning. Coding the function out solved the issue.

 

[Sidewaze Samm]

I wonder if that's because it was just one on so could be mistaken for indicating?

When it was sent through MOT, it had both sides like it

Really? That's my theory shot down then.

My previous zed (the 2.5si mentioned above by Enuff_zed) passed at least one MOT with the indicators showing, before I swapped out the LCM...
Though I can't remember if both bulbs on each side were illuminated or just one on each side. Enuff...?

 

[enuff_zed]

When it was sent through MOT, it had both sides like it

Really? That's my theory shot down then.

My previous zed (the 2.5si mentioned above by Enuff_zed) passed at least one MOT with the indicators showing, before I swapped out the LCM...
Though I can't remember if both bulbs on each side were illuminated or just one on each side. Enuff...?

Pretty sure when I looked it was just one each side, which is why I thought it would pass as the indicator would still show.
Possibly the tester didn't realise there were two bulbs and thought it would inhibit the indicator??

 

[kom458]

Sounds strange, usually if a bulbs out you will get a dash warning light and the indicator bulb on the failed side will turn on to act as a sidelight backup. Have you checked the rear lights for a bulb out in case thats the cause?
Another check would be to scan the car and see if the bulb warning function has been coded out on the car. This can be done using BMW Scanner 1.4 on a laptop, coded my sidelight warning out after fitting led bulbs because although being sold as Canbus error free they wern't when fitted to my Z4 and lit the bulb out warning. Coding the function out solved the issue.

The rear lights all work okay. There is a dash light for the light that's out but I've tried replacing bulbs and it still stays. I don't have a compatible laptop for that unfortunately, if that's the case will probably have to take to BMW

 

[colb]

Can't believe it but my 2.5 has just showed up with the same problem, nearside indicator inside bulb lit up as soon as the sidelights are switched on and dash bulb out warning light illuminated. All lights sides, head, main beam and tail lights as well as side repeaters and brake lights are all working. My first thought was maybe the led bulbs I put in the side lights and side repeaters could be the cause so put the original bulbs back in and cleared the codes. Still got the inner indicator bulb lit up when sidelights turned on. Used BMW Scanner 1.4 to code out all the bulb check functions for every bulb but I still get the indicator inner bulb lit but no dash warning light now. No amount of code clearing will get rid of it. Will have to do some more research into this before looking at putting another module in.
Will keep an eye out on how kom458 deals with his and will update if I manage to resolve the issue, MOT due next September so time on my side with this fault.

 

[colb]

Solved my indicator inner bulb being lit today.
Took the wheel off to get a better look and access to the back of the headlight, checked all bulbs and holders, all were good.
Then took a closer look at the bundle of wires in there and once some of the wires were pulled from the small cut out in the plastic body that supports some of the wires I found the blue, white and brown wires had melted together. Using a pick I separated the wires and found the only casualties were the blue wire and white wire where bare copper was showing in two places. Once separated the indicator light that was staying on went out so looks like the cause was a short from one of the other melted wires that fed the indicator bulb and caused it to stay on as opposed to a bulb out warning function being the cause.
Managed to use tape to insulate the damage, would have used heatshrink but its a bit tight and not much slack on the blue wire to do a solder joint in the area of the damaged outer cover of the wire. Recoded the bulb out warning using BMW Scanner 1.4 and then did a full test of all lights and didn't get any bulb out codes. I had considered using some electrical insulation paint on the damaged wire but local Halfrauds didnt have any. May get some and revisit the damaged wire again and try that paint repair on it. I did ensure all the wires are separated in there just in case there is another heat build up, I didn't tuck them into the plastic cut out support, its a bit small for the amount of wires that should go in there and may have been the cause of the damage occurring in the first place since that showed signs of heat build up.
The damaged blue wire is bottom right in the picture.