The first step, as always, is to do a bit of research (specifically to see if a step-by-step DIY already exists on Bimmerfest or elsewhere).

Unfortunately, there was nothing in the VERY best of E39 Links so I did the typical Bimmerfest search which revealed some potentially confusing "details", e.g.,
- Some BMWs force you to remove the parcel shelf to access the 3rd brakelight
- Many threads caution against brass bulb bases in favor of "silvered" (yet, mine is clearly encased in plastic - or maybe MELTED in plastic as the case may be)
- Most DIYs intimate the bulb removal is trivial; but - it wasn't immediate obvious to me (nor to many of the equally clueless posters).

Here are, for the record, the results from my initial Bimmerfest searches:

Searching Bimmerfest for "E39 Center Brake Light" & "3rd Brake Light", I find a lot of chaff, e.g.:
- Check brake lights ***
- which bulb is burnt out
- Rear Center Brake Light
- 3rd Brake Light Problem E39
- center brake light
- Check Rear Lights?????
- Rear Brake light icon came on today...
- Rear lamp warning display is on in my BMW 528i

None of which were DIYs but this one gave a cryptic warning:
- Check Brake Light
"If you bought the bulbs from Autozone, make sure they're the one's with the silver color base, not the copper color."

I wondered why "silver" and not "copper" color - so I kept searching 'till I found this:
- E39 (1997 - 2003) > How to turn off stoplight out warning on dash?
"do not use the brass based bulbs"

Still, that explained nothing until I saw this from chiefwej in that same thread:
"the resistance reading can be so sensitive that you have to clean the contacts and you can't use a brass based bulb. On my 03 I get a "check brake light" warning if I don't use a stainless based bulb"Googling, I find in the other forum:
- E39 Replacing center/rear brake light (where you access from the trunk)
- E36 DIY: Removing the third brake light (where you remove the parcel shelf)
- E39 How do I replace the center brake light bulb in the rear window?

Where QSilver7 says to look in the owners manual and others say it's in the trunk and easy to access (I had never looked before). People have said it's hard to get out (you don't know when to stop turning).

Unfortunately, most of the pictures in those bimmerforums threads are locked to non registered users ... so I guess I'll just post my own here.

Here is one unlocked picture from QSilver7's post in that forum:

 

Then, of course, I went to the on-line owners manual.

In my case, I located the page reference comparing the cluster warning message with the PDF located at this thread:
- List of all possible BMW E39 instrument cluster text warnings & text messages

Specifically, the reference was:

CHECK BRAKE LIGHTS = P2 = A lamp has failed or the electrical circuit has a fault. Refer to pages 126 & 132 of the owners manual

Unfortunately, while the owners manual is correct, unless you've done it before, I would say that the picture and description is, shall we say, somewhat lacking in clarity.

 

The next step was to open the trunk, crawl inside, head first, feet in the air, back on the trunk flooring, to look upward, not in the lid itself but in the part of the car underneath the rear window and rear parcel shelf, to see the black plastic "cover" under the third rear brake light itself.

 

Getting the lay of the land, at first, I couldn't figure out HOW to remove the cover plate. (Mistakenly, as it turns out), I held the entire black rectangular housing in my hands and couldn't budge it downward. I thought that was weird.

So, I (again mistakenly) removed the nut shown in this picture.

Alas, that nut merely allows you to slide the brake light assembly an inch or so forward or backward, apparently to align it with the rear window, so, in this (idealized) DIY, you would not remove that nut.

 

As with all things obvious in hindsight, the simple "trick" to accessing the center rear brake light bulb is simply to insert a 1/4 inch screwdriver (or your fingernail) into the rearward-facing slot built into the rectangular plastic assembly.

Then, you simply twist the screwdriver 90° to disengage the thin plastic bottom plate from the larger mass of the black rectangular plastic assembly.

This separates the friction fit plate from the assembly, and the plate will fall to the trunk floor by gravity.

 

You will see the bottom of the brake light bulb assembly once that thin cover plate is pried off.

You twist a quarter turn (normal counter-clockwise direction) to free the bulb assembly from the holder.

The bulb assembly, still clipped to the harness, will then fall downward by gravity as shown in the photo below.

 

Reading the numbers stamped on the black plastic bulb surrounds, we find a date wheel with "01" in the center and the arrow pointing to the number "4", probably indicating it's the original bulb holder, manufactured in April 2001 for this November 2001 build date 2002 BMW 525i.

Also, we see "BMW8364780", "178 056", "32CP", "P21W", which probably correspond to the part number, candlepower, and wattage.

I unclipped the harness connector by squeezing at the outside of the "ears" and pulling apart the brake light assembly from the harness connector.

 

Comparing those numbers to Realoem (Lighting => Third stoplamp), we find that the bulb and the "bulb socket" are separate parts (even though mine seem to be melted as one):

03 Longlife bulb 12V 21W 1 63217160790 $2.38
04 Bulb socket 1 63258375599 $5.40

Interestingly, no number matches "BMW8364780"; but googling reveals Crevier BMW posts in other forums which intimate it's the part number for the socket (even though Realoem lists a different part number for the socket).

Notice that BMW superceded the original bulb part number (07509063574) at least once (63216926920) and maybe even twice (63217160790) - which may be due to the melting you see in my bulb housing (63258375599).

Do we know why BMW changed bulb part numbers & what the differences may be between them?

 

What you're left with, after you unclip the rabbit-eared harness connector is the bulb and bulb assembly (in my case, melted together) in your hand, and the harness clip dangling from the vehicle.

 

Try as I might, I wasn't able to disengage the 3rd brakelight bulb from the plastic bulb socket (for example, to determine if it's brass or silvered).

I can wiggle it. But the bulb won't come out of the melted bulb socket.

Can someone without a melted socket tell me what's the bulb removal method from the bulb socket?

Is it a press and twist? Is it a pull-straight-out?

(I read all the DIYs quoted and none seem to say how to remove the bulb itself from the surrounding bulb socket - and - the realoem picture offers no clues.)

 

Try as I might, I wasn't able to disengage the 3rd brakelight bulb from the plastic bulb socket (for example, to determine if it's brass or silvered).

This thread intimates the bulb part number is SYLVANIA/OSRAM #7506:
- E39 (1997 - 2003) > Rear Brake light icon came on today...

Looking up that well-known bulb, I see it's the push-down-and-twist-to-the-side type bulb.

I'm assuming that isn't working for me because of the melted bulb socket.

The main unanswered question is WHY is the bulb socket melting (it seems to melt on quite a few people).

Coupled with the fact that BMW superceded the bulb part number numerous times, I wonder if the Sylvania 7506 is really the right bulb or not.

Do we know 'why' the center brake light bulb socket tends to melt?

 

In response to the CHECK BRAKE LIGHTS cue on my instrument cluster yesterday, I checked and found that this 3rd brake lamp was in fact the culprit. Proceeding to open the rear deck trap door and extracting the bulb, I found EXACTLY WHAT YOU HAVE POSTED ABOVE!!!
The bulb was melted into the base of the socket. I did not have the visible melting at the top edge as shown here, but the bulb was clearly fused into the base of the socket. So I too will be ordering a new socket.

Thanks for these helpful photos; I felt better knowing it wasn't unique to my car.

 

I found EXACTLY WHAT YOU HAVE POSTED ABOVE!!! The bulb was melted into the base of the socket.

Thanks for replying. I was wondering why nobody answered my request for why the bulb sockets are melting when the correct (in my case the OEM) bulbs are in the socket.

It's not like there's any way we can over-use the brakes; so, it must be a design flaw of some magnitude.

Do you have a picture of your melted socket?

I think it's time we started collecting them, as this isn't listed in the top-30 common repair items in the BMW E39, but, it seems, from the prevalence, that it should be.

 

No need to spend inordinate amounts of time on this....simply use the correct 7506 bulb (which has the correct nickel plating), and if the socket is melted, get the latest version from the dealer (why even bother trying to remove the bulb or reused the melted socket?). You have little choice in what bulb to use, as the LCM will show a "brake light out" displayed on the gauge cluster if you use a brass based bulb, or one of a different wattage than specified. So use the correct bulb specified, and replace the socket if damaged....end of story.

(btw, the problem is mostly likely the socket...too much resistance causes heat, and the subsequent melting...I suspect the contacts are simply too small and BMW probably corrected it in later versions, as show by the newer part numbers)

I personally, have never had this problem with my car, and I have replaced the third brake light bulb a couple times over the 161k miles my 2001 540 has...

Now I HAVE had a few melted front turn signal bulbs...not the socket mind you, but the yellow bulbs plastic base. Obviously caused by the crappy bulb and socket design. The dealer says when it happens, it is best to replace the socket, as well as the bulb....which I have followed, but it continues to happen....not often...it actually takes YEARS until it melts. I have replaced the left side socket a couple times over 10 years of ownership, and the right side once. Not something I really worry much about, but I do keep a spare front turn signal socket handy in my spare parts collection, along with a spare drain bolt, oil filter rubber mounts, and oil filter o-ring, and copper drain bolt washers...

 

simply use the correct 7506 bulb (which has the correct nickel plating)

My question, since a LOT of people apparently have melted sockets, and, since there are multiple 21 watt bulbs listed in Realoem, only one of which was ENDED, is whether or not the 7506 'really' is the correct replacement bulb (especially since the 7506 is reputed to be 20% higher wattage than the BMW bulb).

if the socket is melted, get the latest version from the dealer

That won't work.

The problem with that is that the "latest version" is apparently the same design as the one that melted. That is, I see no ENDED part numbers for the bulb socket; only for the bulb itself.

So, replacing the socket just pushes the tin can down the road. Solves nothing but time.

(why even bother trying to remove the bulb or reused the melted socket?).

Forensics. Knowledge. Truth.

We're trying to get to the bottom of this. It's all about forensics.

If, for example, we autopsy every future burned bulb socket, and we find that it's always the 7506 bulb (hypothetically), then, that would be an indication that the bulb is the culprit. Likewise if the bulb was always a Sylvania bulb (again, hypothetically), the culprit would be the Sylvania brand.

Just as we're trying to get to the bottom of which FSUs fail most often, it's a useful endeavor to simply identify which bulbs were found in the melted sockets.

Point is, we're NOT just trying to fix the problem. That takes no brains, and almost no effort (i.e., you just buy a new bulb and socket and you're done, as you said).

No. That's not what we're trying to do here. Here, we're trying to figure out WHY so many rear brake light sockets are melted.

That's going to be a team effort. We need data from everyone that experiences this problem, particularly what bulb is it that's melted in there. (I, for one, haven't figured out what bulb I had in there; but I suspect it's the original bulb.)

You have little choice in what bulb to use, as the LCM will show a "brake light out" displayed on the gauge cluster if you use a brass based bulb, or one of a different wattage than specified.

That's not exactly true. It's clear, since there are so many burned sockets, that we have little choice IF (and that's the problem) ... if we actually KNEW which was the 'right' bulb.

But, as far as I see, nobody knows what's the right bulb (at least nobody has proven to me they know).

Why do I say that?
- Because there are TWO different part numbers in Realoem (in addition to the ENDED number), all of which are the same wattage - so 'which bulb' is it?

• 2002 525i --> 07509063574 12 volt, 21 watts, ENDED
• 2002 525i --> 63216926920 12 volt, 21 watts, UP TO 12/2004
• 2002 525i --> 63217160790 12 volt, 21 watts, no further information

- Note that the 7506, apparently, is a different wattage than specified. The 7506, according to the information above, is a 25 watt bulb - but BMW seems to specify (in Realoem) a 21 watt bulb.

That's about a 20% difference in wattage between the BMW bulb and the 7506!

So use the correct bulb specified, and replace the socket if damaged....end of story.

Not so fast. What's the correct bulb?

• 07509063574 12 volt, 21 watts <-- it's not this 'cuz it was ENDED
• 63216926920 12 volt, 21 watts <-- it could be this
• 63217160790 12 volt, 21 watts <-- it could be this
• 7506 13.5 volt, 25 watts <-- the specs don't sound right to be this

the problem is mostly likely the socket...too much resistance causes heat, and the subsequent melting...I suspect the contacts are simply too small and BMW probably corrected it in later versions, as show by the newer part numbers)

I'm not saying it's not the socket, but ... the otherwise-reasonable argument you showed doesn't seem to make sense (to me) simply because I see no evidence that BMW superseded the part number for the socket.

That is, the socket does NOT show any ENDED or newer part numbers!

In summary:

1. It's not clear (to me, anyway) what is the cause of the problem.
2. It's not clear (to me) what is the right bulb to purchase.
3. It is clear that the socket needs to be replaced (with the same one).

We definitely need tribal help to narrow this enigma down to the root cause & solution.

 

Here's the melted socket with the base of the bulb still stuck inside it.

 

That's very interesting. Are you sure it was the right bulb? (It probably was, but, it's something we should check.)

Methinks, if it's the right bulb, then even the 'right' bulb is drawing too much current (based on anecdotal evidence).

This Autozone site says the bulb draws 1.9 amps.

I wonder if we put a resistor inline, to drop the current draw to, say, 1 amp, whether it would still work or not. What do you think?

 

I can't confirm whether it was the right bulb or not as i wasn't the one who installed it. But I received the new socket today and I'm ready to get replacement bulbs, so do I go w/ the 7506's or not?
I will likely check to see what I have in the primary brake lights; since they come as a pair, I will install the two new lights in the main lights, and take one of the removals for the 3rd brake light, assuming they are all the correct bulb.

 

I received the new socket today

I haven't ordered mine yet. Where did you get it from, and how much (if I may ask)?

do I go w/ the 7506's or not?

From the information provided so far, the 7506 is 20% higher wattage than the BMW bulb (P/N 63216926920 or 63217160790).

So, at this point in time, it seems (based only on the data in this thread) that the 7506 is the WRONG bulb for this application. (But, we need more data to confirm or disprove that hypothesis).

 

This reply, just now, from the thread below, points us in the right direction:
- E39 (1997 - 2003) > Check Brake Light

BMW used a cheap plastic that was not capable of withstanding the heat. I work at the dealer, and we once had an engineer come by, he told us BMW saved money everywhere they could. BMW shaved almost $5,000 worth of things on each individual car here and there from the original blueprint, and this happened to be one of those things they cut back on.

 

so can we find a less heat sensative socket to install then or are we stuck with the simply reinstalling one that we know will fail with time?

 

so can we find a less heat sensitive socket to install?

Dunno. I suspect we can.

I looked on the E46 side of the house:
- E46 (1999 - 2006) > Joining hands to solve a common failure of the center brake light (socket melted)

But, unfortunately, I can't visualize their bulb socket from the diagram:

 

BlueBee:
i picked up the replacement socket from Auto Parts Warehouse @ $5.95 plus tax plus shipping. But I also needed an oil filter so that reduced the overall impact of the shipping for a plastic piece that should have/could have been mailed USPS for 75 cents.

 

i picked up the replacement socket from Auto Parts Warehouse @ $5.95 plus tax plus shipping

They don't seem to have the part number listed when I searched:
- 04 Bulb socket 1 63258375599 $5.40

 

My dash light is on so I changed the bulb(tried two BMW and Autozone) No evidence of burned socket,but does not light.Is there a fuse I can check and what #?

 

You have to remember that we can not SEE your dash or your car...so when you speak vaguely (without specific detail) it is unclear to us as to what your really saying.

We don't know what dash light is on because there's many or them, and we don't know which bulb or bubl socket that is not lighting up...again, because you just mention in general that "a bulb" is not working.

Help us help you better, give more details and be specific...is the dash light that is on appearing in your graphic display or is it one of the other warnings in the instrument cluster...is it a brake light or onen of the other bulbs in one of your rear tail light assembly...is it on the left, right, or the center brake light?

For example, if you told us that the warning for the rear passenger side tail light was illuminated on your instr cluster...and that you changed the rear pass brake light and the warning was still there...would be much more specific and is very clear to others that can't see your car or what you did versus "my dash light is on, I changed the bulb, the warning is still there".

If the problem is not that your center brake light (on the rear parcel shelf) isn't the culprit, then you need to check the wiring loom that goes from the trunk up to the LCM.

 

Are you people for real? Talking about replacing a bulb like it is rocket science? Relax a bit and get a life. It is good practice to maintain your car, but come on. Stop spending so much time talking about non sense. Go out and have a coffee or something, you will enjoy it more....

 

Stop spending so much time talking about non sense.

Methinks you misunderstand our intention.

We're not just trying to 'throw parts' at the problem. We 'know' you can replace anything and it is 'repaired'.

What we try to to is find out the underlying engineering defect that caused the problem in the first place.

For example, Bill (540iman) found a great way to test wheel speed sensors; Raj found & resolved the brittle VANOS seals problem; cn90 has found & resolved many defects, e.g., with the ambient air temperature sensor location; (skipping many others); and I even 'found' a simple solution to the broken PBT headlight adjusters that costs $5 for both headlights (as opposed to nearly a thousand dollars).

The point is that we don't just 'fix and forget' on this forum!
And, we don't just 'throw parts' at the problem.

Any numbskull can do that!

We, on the other hand, enjoy ardently discussing pixel tape solutions, comparing vapor barrier solutions, suggesting window regulator solutions, explaining trunk loom solutions, postulating stinky gym sock AC solutions, etc.

You, on the other hand, can help by answering some of the unanswered questions. For example, why did BMW specify numerous bulbs - yet - the wattage and configuration of the bulbs appears (upon first inspection) to be the same?

Also, what is the plastic used in this part and why does it melt and does that melting only occur with the original bulbs or with the replacement bulbs.

And, best of all, for the intelligentsia anyway, what is the engineering solution so that the bulb socket doesn't burn up with long-term use?

Note: Only the proles simply 'throw parts' at the problem without caring to understand the underlying engineering cause & effect.

 

03 Longlife bulb 12V 21W 1 63217160790 $2.38
04 Bulb socket 1 63258375599 $5.40

Same with Oembimmerparts ...

But, others have them in stock:

Bavarian:

ECS Tuning:

EAC

Along with the bulb (although it's hard to tell if it's the 'right' bulb since Realoem lists multiples):

 

For the cross linked record, another poster today reported a melted center brake light socket:
- E39 (1997 - 2003) > High mount third brake light

I went to Auto Zone to buy a replacement bulb for the third brake light. I bought the bulb according to the computer query and went out to replace the bulb. Well I pulled the bulb and tried to extract the bulb from the black retainer but had to break the bulb and it still would not come out. It looks like the bulb melted to the black ABS plastic or should be replaced as a whole unit...

Please let me know if I missed something somewhere. THANKS!

 

While most bulbs are easy-as-pie to figure out, this center brake lamp often stumps the novice.

For example, a newbie posted today the following thread:
- E39 (1997 - 2003) > High Level Brake Light

Where it was asked:

How do you access the bulb for the center, elevated brake light on a 528i E39?

The answer is in this thread!

That's what I love about DIYs ... they help everyone the moment they're written.

BTW, one "solution" to the melted socket might be simply to remove the cover (assuming that allows better cooling).

 

For the cross-linked record, in that previously referenced thread:
- E39 (1997 - 2003) > High Level Brake Light

Another user posted his (apparently) unique problem with removing the center high brake lamp.

It seems as if a monkey got stuck in the trunk, and, apparently tried to chew his way out of the trunk via the center brake lamp assembly!

• The cover was missing
• The linear tabs that hold the cover on were broken
• And, the three tabs that hold the socket in place were also missing

Interestingly, the normally problematic socket was, in his case, actually the only part in good working order!

Pictures for your edification are below.

This first one shows the missing cover covered with electrical tape to hold the bulb & bulb socket in place:

This unique picture is looking directly upward from the trunk up to the brake lamp - and it shows the three keyhole tabs are brutally busted out:

And, this picture shows that the one thing that is undamaged is the bulb socket itself, with three intact keyhole tabs!

I guess this goes to show that it wasn't easy for whoever it was that did that damage to figure out how to remove the center brake lamp socket from the center brake light assembly!

 

What about a LED replacement for the bulb or bulb & socket? LED should be less heat. Anyone know what it takes to adapt LED and still make the failed bulb detection circuitry happy?

 

What about a LED replacement for the bulb or bulb & socket?

I briefly explored that option with the E46 (LED) crowd a few posts above:
- E46 (1999 - 2006) > Joining hands to solve a common failure of the center brake light (socket melted)

Googling, I see others 'said' they did it (but I wonder since they provided no real details):
- 3rd brake light socket fried

I put a red LED and resistor in mine to transfer the heat to the led's outside resistor. Been in about a year now and so far so good.

In addition, more research reveals another DIY, although it's text only:
- How to Change an E39 3rd Brake Light

This E39-issues site says the socket can fail in the following ways:
- E39 Common Problems

The contact tabs on the sockets corrode or bend. These can frequently be cleaned up. Also, when the center bulb fails, the dash display shows it as one of the corner lights. The socket for the third light sometimes melts.

Best of all, was this Roadfly page which tries to understand WHY the socket fails:
- 3rd brake light socket fried

I ended up buying a new socket and decided to cut the old one in half to see what was up. As I figured, the socket melted where the bulb contacts the socket on the side.

The real problem with this type of socket is the contact is a thin strip of brass wire that runs along the side of the socket. With time, it begins to corrode and makes poorer and poorer contact with the base of the bulb. Then it begins to heat, eventually melting the plastic. When you replaced the bulb, you were temporarily improving the contact, but it was a temporary benefit. If you could have cleaned in the socket with emery cloth or something like that, the socket might have lasted. It's a poor design.

 

For the record, according to this thread today:
- E39 (1997 - 2003) > sollution to broken bulb message (while they are not broken)

Apparently, one cause of an errant bulb-out cluster message could be the burned center brake light:

I found out what the problem was. The center brake light.