DIY Fix:Dim rear lights or random bulb warning on E46 Saloon

Got rear bulb failure warning on dash but no bulb is blown?
Left or right rear lights dim?

Seems that the E46 saloon (don't know about the coupe) has a problem with the wiring loom. I know this has been covered before but no pics are included to show the problem. So I took the chance to take some when I fixed my friend's 320d which had the problems I mentioned above.

Quite shocked from the wiring situation.

I removed both plugs from the rear headlights. This is a picture of the plug. You can clearly see where the problem is:


Although thicker wire, brown plug (ground) seems not able to handle the current from the tail light system.



Same applies for the plug on the rear light assembly. Plastic is melted around the plug and there are arc signs.



As a workaround, I completely bypassed the ground (brown) connection plugs by soldering a thick brown wire straight on the tail light metal strip shown above. Using a multimeter, find the metal strip that ends to pin #2 (ground) and solder on that. The ground strip has a ground terminal where you can use some kind of plug if you want to avoid soldering.

If you are going the solder way: Good to use some sandpaper first on the metal strip and some soldering paste to make things easier. Had to set my soldering station to 450 degrees celcious to solder on that strip. I then connected the new wire with the car's brown wire.

Left around 15cm of wire just to allow the bulb holder to be removed for bulb changing.

Problem solved.

Originally Posted by paraklas

As a workaround, I completely bypassed the ground (brown) connection plugs by soldering a thick brown wire straight on the tail light metal strip shown above. Using a multimeter, find the metal strip that ends to pin #2 (ground) and solder on that. The ground strip has a ground terminal where you can use some kind of plug if you want to avoid soldering.

If you are going the solder way: Good to use some sandpaper first on the metal strip and some soldering paste to make things easier. Had to set my soldering station to 450 degrees celcious to solder on that strip. I then connected the new wire with the car's brown wire.

Left around 15cm of wire just to allow the bulb holder to be removed for bulb changing.

Problem solved.

Hey I had the same problem but your car is probably newer since it has 8... and mine only has 6.

Basically I bought a new connector, wire, and a whole inside taillight assembly. Then took the old connector, and unclipped this white peice that just held in all the wires. On yours it looks like it would be the black peice. Then you just plug it into the new connector, and cut the bad wire, and re-attach the new wire, and new plug and clip it into the new connector and wa-la! Your taillight should work.

Steve

Now I just have a hood problem... LOL

There's a technical bulletin for this issue which requires upgraded bulb holders and plugs from BMW. I hope you got the upgraded parts. Also modifications in wiring are required.

If the plugs/holder are not upgraded, the same thing will happen.

The pictures are from a 2002 E46

My E46 saloon is 5 years old and I have owned it 18 months, during which I have had several rear bulb warnings. I have cleaned contacts, cleaned plugs and sockets on light units, sprayed all contacts with contact spray only to find the warnings would re-appear within a day. Being an automotive engineer by trade I applied a little consumer logic, and that is. All bulbs are manufactured to fail and so I checked with the previous owner and he had never changed a rear bulb, but had often had the rear bulb warning. So were the bulbs wearing, the set resistance in the filaments increasing, they looked OK but they had been in the car for 5 years. I bought a full set of rear light bulbs including the interior boot (trunk) lights, a set of BOSCH bulbs from a BOSCH dealer. This was three months ago and I haven't had a problem since, the cost was just over £20 a little less than a BMW main dealer would charge. I hope this is of help.

Originally Posted by paraklas

There's a technical bulletin for this issue which requires upgraded bulb holders and plugs from BMW. I hope you got the upgraded parts. Also modifications in wiring are required.

If the plugs/holder are not upgraded, the same thing will happen.

The pictures are from a 2002 E46

Yes I bought the parts and upgraded it... but I'm surprised BMW doesn't pay for it... because it's their fault, and its a very common problem.

Same problem on my 2002 325i sedan.

Since I'm not as adventurous with high current electrical circuitry, I had a mechanic diagnose the problem and fix it. Instead of soldering a new ground wire, he did the connection with a lug so the cable can be entire disconnected if need be.

The block showing the burnt contact (bottom row, second in from the left):




The connector showing the burnt pin hole:




The new ground connection:

I have this too, on my 2003 330i, on both sides.

I'll use operknockety's fix.

fukit im just gonna change the taillights to an aftermarket one with no bulb holder

I've got same happening on my '99 ...



Am I going to have problems installing an aftermarket one? Should I go ahead and order a new connector from the dealership?

Alright this happened to me too and i lost most of my rear lights. My buddy is a BMW Tech and basically sent me teh following walkthrough:
what you need is:
-(2, one for each side)8-pin connector housing- #12 52 7 519 956

-(2, one for each side) comb-type connector (housing) 3-pin #61 13 1 393 718. this is actually a cover for the next part number

-(1) comb-type connector (contact strip) #61 13 1 387 150. this will come with multiple strips, just need to cut off 3 strips for each tail light. you will be taking 3 wires and putting them all on this strip, connecting them all together.

-(6) flat contact for comb-type connectors # 61 13 1 387 144. you will crimp these to the 3 wires on each side to plug onto the strips above.

-(2) flat plug-in sleeve #07 11 9 975 531. will go from the contact strip, to a spot on your bulb housing, this is the extra ground you are adding.

-(2) blade contacts #12 52 1 433 217. these will go on the end of the ground wire and into the 8 pin connector that got all burnt up.

(2) crimp connectors #61 13 8 353 747. will go from the wiring harness on the car, to the contact strip.

you will also need "bulb carriers" for both taillights, if they pins are damaged on them, you will need to unplug them and check

Tools listed on the bulletin:
Crimping pliers #83 30 0 494 159

Wire strippers #81 69 0 416 257

Pliers for comb-type connectors #90 88 6 619 041

Die-plate for comb-type connectors #90 88 6 619 042

you need to remove all the wires from the old 8 pin connector that plugs into the bulb housing, and transfer them to the new connector, do one at a time so you know where each one goes. if you really want to, you can get just the (2) blade contacts #12 52 1 433 217 to plug the new ground wire into the connector and (2) flat plug-in sleeve #07 11 9 975 531 to plug onto a spot on the bulb carrier. you can splice all 3 wires into one with whatever butt connector you want, or even just solder them, in that case you could prolly do without the #12 52 1 433 217 and solder the wire right onto the bulb housing.

I plan on picking the parts up tomorrow.

I had this problem on my 02 sedan, all you have to do is splice into the brown wire and run a parallel connection to the ground plane tab. My plug is still fried where the ground wire is, but everything works perfect now. Cant remember the last time I saw a bulb out warning. Check out this link:
http://forum.e46fanatics.com/showthr...469&highlight=

ive been getting this phantom rear bulb out indicator on my 2003 325xi.. do you guys think its the same thing? i dont ahve any bulbs out... ive checked them all several times and couldnt find a dead bulb. does bmw pay for the replacement parts/labor since there is a bulletin on it?

Pay?!? lol.

They sell an updated wiring harness to fix this issue. best to check the connectors and use a new ground.

I'm not much of a DIY'er, and not much of an electrician at that, but I did the brown wire splice. I went to the hardware store and probably bought too thick a gauge of wire. It's a bit chunky of a fix, but I spliced my new wire to the brown one and then taped it up with electrical tape. Since my tail light assembly (the part that the bulbs go on) is old and didn't have the for the 1/4" electrical connector, I found another spot where I could put in a grounding screw. I scratched up the surface with my plier, screwed it in and squeezed it all together. Voila, it worked.

I've ordered some aftermarket LED lamps, figure I'll need a new 6 pin connector housing (and to figure out how to connect the wires to that housing) when the parts get here. Thanks for all the help and photos, guys!

Originally Posted by ports

ive been getting this phantom rear bulb out indicator on my 2003 325xi.. do you guys think its the same thing? i dont ahve any bulbs out... ive checked them all several times and couldnt find a dead bulb. does bmw pay for the replacement parts/labor since there is a bulletin on it?

Sounds like the same symptoms I had. Pull the tail assembly out, disconnect the connector block and see if there are any burnt pins or melted plastic.

Originally Posted by danGIMP

I'm not much of a DIY'er, and not much of an electrician at that, but I did the brown wire splice. I went to the hardware store and probably bought too thick a gauge of wire. It's a bit chunky of a fix, but I spliced my new wire to the brown one and then taped it up with electrical tape. Since my tail light assembly (the part that the bulbs go on) is old and didn't have the for the 1/4" electrical connector, I found another spot where I could put in a grounding screw. I scratched up the surface with my plier, screwed it in and squeezed it all together. Voila, it worked.

I've ordered some aftermarket LED lamps, figure I'll need a new 6 pin connector housing (and to figure out how to connect the wires to that housing) when the parts get here. Thanks for all the help and photos, guys!

let me know how that goes for you, im getting led's at the end of the month.

Hey guys, I ve been having this issue for about 6 or 7 months now, and never got around to looking for a fix. I was at the bmw dealership and a cool tech out there told me that they see this issue all the time and that its mainly due to just poor grounding on this part of the vehicle.

On my way home i stopped at the part store and picked up some connectors...I only needed 4, but paid for 2 boxes of 12 for the type of connectors I needed...total about $5. I used some 14 gauge wire laying around from my car pc install and did the fix today...and it works perfectly.

I m lucky enough that my wires and harnesses where not melted at all. I was getting the light notification on both tails, which was fairly annoying, as it would come and go every other day. I recommend to anyone to do this fix, even if you do not get the annoying bulb notice.

It took 30 mins to do, between taking out the carpet, crimping the wires, hiding them, and hooking everything back together.

I took some pics to add to the OP's post. I didn't see the need to solder, but to each his own...hope this helps.



Connector for the tab on the tail



Connector to the ground



Both tail boards removed



The metal tab where the grounding connector goes on each tail (Right tail here)



Both tails with the connectors and wire...about to go in the car



Done with the left tail...grounded to the cd changer mount(left side of the bolt)...where I have other grounds i used for my car pc stuff.



Of course, I completely bypassed the ground (brown wire on the both tail light harnesses)from the harness to avoid any issues down the line, so I removed it from the harness and put EL tape on it...did this on both sides.



Done with the right side...grounded directly to the battery here...again I have 2 other grounds from my car pc stuff as well.

Hope this helps.

Did mine the other day, very easy fix and a good write up. I bought some little 90' connectors at pep boys, pulled the brown wire out of the socket, cut off the end, stripped it, crimped on the new connector and plugged it up to the tab. 10 mins in the dark and no warning light since.

thanks top stuff this i almost paid £40 for a garage to have a look at this problem. Good job i used the search thing. Thanks

Has anyone seen this problem with the front (corner) turn signal lights? I started getting this problem with the rear right two weeks ago and a few days ago it's intermittantly affecting the front right turn signal.