Trunk Light

[Richard Madison]

Scott:

On both a 1971 USA model and a 1969 Euro model, the trunk light came on when the truck was opened...had a pressure switch that released when the trunk lid came up. The light was on when the lid was open even if the lights were off and the key was not in the ignition.

If I was at a car show with the trunk open all day, I unscrewed the bulb.

Richard M, NYC

[thelews]

Having the advantage of having both a 71 280 and early 67 250 side by side, I thought I'd help.  280 trunk light on all times, no interior light with tail light.  250 trunk light on with tail light and interior light from behind.

One can see the change to more cost saving materials in the 280 assembly (plastic) also.  280 first, then 250.

[thelews]

My solution to the broken trunk light loom.  Makes for easy removal of the lid, if needed.

[scoot]

quote:Originally posted by 280SL71

Scott:

On both a 1971 USA model and a 1969 Euro model, the trunk light came on when the truck was opened...had a pressure switch that released when the trunk lid came up. The light was on when the lid was open even if the lights were off and the key was not in the ignition.

Hi Richard -   So my question still stands (since I don't know if a 1969 euro SL has the kind of tail lights that illuminate the trunk or the kind that is later...)   My car also has a switch for when the trunk is open.   Is it true that cars that originally had the old style tail lights (meaning that light comes through the back of the tail light into the trunk) _ALSO_ were cars that had the separate trunk light only operate when the lights were turned on.  OR at some point in time did MB just decide to make the trunk light switch hot always independent of the light switch position, and independent of what type of tail lights are on the car...?  I'm just trying to see if there is a correlation here or not...    Thanks!  Scott

[thelews]

quote:Originally posted by scoot

ALSO_ were cars that had the separate trunk light only operate when the lights were turned on.  OR at some point in time did MB just decide to make the trunk light switch hot always independent of the light switch position, and independent of what type of tail lights are on the car...?  I'm just trying to see if there is a correlation here or not...    Thanks!  Scott

They all have the switch operated trunk light in the lid, to my knowledge.  That's where the wires following the trunk hinge go to in my picture below.

[Naj ✝︎]

quote:Originally posted by thelews

They all have the switch operated trunk light in the lid, to my knowledge.  That's where the wires following the trunk hinge go to in my picture below.

According to 230 SL parts book, the switched trunk light was introduced from 042 012467.

Prior to that you had the little windows in the back cover of the rear lamps.

naj

[thelews]

Goes to show what I know (hence my hedge)!  One always has to be careful of "free" information (opinion).  Thanks for the clarification.

[scoot]

quote:Originally posted by naj

According to 230 SL parts book, the switched trunk light was introduced from 042 012467.

Prior to that you had the little windows in the back cover of the rear lamps.

Clarification:  Prior to that AND AFTER THAT you had the little windows in the back cover of the rear lamps until the rear lamp style was changed to the type with the plastic backs.  So my questions still stands:  Does the transition from the switched trunk light being hot only when the lights are on TO the switched trunk light is always hot correspond to the switch from the old-style tail lights to the new-style tail lights?

[rjmarco]

I'm glad I read this series.  I thought my trunk light didn't work.  I switched on the head lights and the trunk light illuminated.  I have a 1965 230 SL.

[Paul & Dolly]

Inspired by this historic thread , I investigated and found a light and switch unit in the lid    - but  the wires had been cut and taped over at the loom, and the other half pushed inside the lid    !

I have reinststed them and I now have an operational "trunk / boot" light - albeit with a corroded switch that I must fix.

My car is RHD May 67 - an early 250 SL - it has the Plastic Light units, and the "Trunk/Boot" light is onlyn operational when the car lights are on.

[dwahi]

most German cars had this as standard...even my 1990 VW boot light only came on with the parking lights! Looks like they never changed this thinking...that you only need the light when its dark and you have the lights on...a bit Germanic!!:)

[114015]

So my questions still stands:  Does the transition from the switched trunk light being hot only when the lights are on TO the switched trunk light is always hot correspond to the switch from the old-style tail lights to the new-style tail lights?

Scott,

Fairly correct. This was changed over some time during the production run.
Earlier trunk lights were illuminated by a grey-blue wire, and that indicates in the same way as instruments lighting: only illuminated when (at least) parking lights are switched on.
Later on this was changed to a red wire (with yellow and white marker lines) indicating it was/is powered by constant + without the aid of the parking lights.

I do not exactly know when this change was ... possibly with the change of the taillight design after serial no. 007938 but this does not mandatorily need to be connected to this change.
Parts list says that the main wiring harnesses and the tail lamp harnesses were changed during production (of 250/280) but the list does not indicate the exact serial number ...

I'll look this up in the Engelen.

most German cars had this as standard...even my 1990 VW boot light only came on with the parking lights! Looks like they never changed this thinking...that you only need the light when its dark and you have the lights on...a bit Germanic!!:)

Ahem, no.
Of cause, I understand you making "jokes" about "Germanic"ism or so...
... that's fine
... but I don't think this is just true in this case.
Volkswagen always had some weird "money-saving" issues with this kind of equipment while MB performed that change already some 20 years earlier - and I believe BMW as well.



Achim

[Paul & Dolly]

[Earlier trunk lights were illuminated by a grey-blue wire, and that indicates in the same way as instruments lighting: only illuminated when (at least) parking lights are switched on.
Later on this was changed to a red wire (with yellow and white marker lines) indicating it was/is powered by constant + without the aid of the parking lights.

I do not exactly know when this change was ... possibly with the change of the taillight design after serial no. 007938 but this does not mandatorily need to be connected to this change.]

Achim -

As I said my early 250 SL RHD has the plastic light units, but the blue/grey wire - powered with side lights.
Do you know where the blue/grey wire originates from in the car, the circuit diagram (2) shows it as Fuse (1), but this is not so for my car, and I would like to change it over at source so the light would always be available, rather than run a new cable through.

Thanks

Paul

[dwahi]

Hi Achim, yes, the comment was in was in jest, so hopefully no offence taken!

Scott,

Fairly correct. This was changed over some time during the production run.
Earlier trunk lights were illuminated by a grey-blue wire, and that indicates in the same way as instruments lighting: only illuminated when (at least) parking lights are switched on.
Later on this was changed to a red wire (with yellow and white marker lines) indicating it was/is powered by constant + without the aid of the parking lights.

I do not exactly know when this change was ... possibly with the change of the taillight design after serial no. 007938 but this does not mandatorily need to be connected to this change.
Parts list says that the main wiring harnesses and the tail lamp harnesses were changed during production (of 250/280) but the list does not indicate the exact serial number ...

I'll look this up in the Engelen.



Ahem, no.
Of cause, I understand you making "jokes" about "Germanic"ism or so...
... that's fine
... but I don't think this is just true in this case.
Volkswagen always had some weird "money-saving" issues with this kind of equipment while MB performed that change already some 20 years earlier - and I believe BMW as well.



Achim

[114015]

As I said my early 250 SL RHD has the plastic light units, but the blue/grey wire - powered with side lights.
Do you know where the blue/grey wire originates from in the car, the circuit diagram (2) shows it as Fuse (1), but this is not so for my car, and I would like to change it over at source so the light would always be available, rather than run a new cable through.

Hello Paul,

Unfortunately these changes are not all accompanied by corresponding official Mercedes wiring diagrams.
Basically the early taillight versus late taillight assembly does not necessarily has to do anything with the separate trunk light located in the trunk lid.

If  the wire for your separate trunk light is grey-blue this indicates the older style wiring and as such the trunk light's illumination only with (at least) parking light on, but no independent operation.
In this case you must follow the reverse direction of the grey-blue wire within the harness, and if I am not wrong here it should go to fuse no. 7 instead of no. 1.
Now you need to find _that_ grey-blue wire on fuse 7 and not mistakenly disconnect the grey-violet (grey-purple) wire (which goes to the instruments lighting). Disconnect only the grey-blue wire from the fuse box (which goes to the trunk light) and redirect it to fuse 1 or (better) a separate fuse.

That should do the job.

Good luck,

Achim
(wiring harness aficionado)

[Paul & Dolly]

Thanks Achim,

Is this a job accessed from inside the car footwell ? or can the fuse box be easily removed from the engine compartment side, to give easier access to the wireing ?

I have just overhauled the drivers side under dash / footwell cover , and found access in the footwell / pedal area quite difficult !

I found a lot of posts about the under dash covers, could not find them in the WiKi - I am doing a lot of "Previous Owner Neglected" jobs at the moment, and take pictures as I go, so I hope to learn to how add to the WiKi this Winter -  and hopefully add some content.

Paul

[114015]

Is this a job accessed from inside the car footwell ? or can the fuse box be easily removed from the engine compartment side, to give easier access to the wireing ?

Hello Paul,
Sorry please for the late answer.
Answer to your 1st question is yes.

Answer to your 2nd question is ah no. 

I have just overhauled the drivers side under dash / footwell cover , and found access in the footwell / pedal area quite difficult !

Not only you. It _is_ a pain. Sadly...
You can unscrew the fuse box from the engine bay side after removing its lid and seal. Push the fuse box carefully towards the underdash compartment. Then you have a little more access.

Only possibility I see ....

Good luck!
Achim

[Paul & Dolly]

Thanks Achim,

I am not so agile as to want another session in the footwell - so Plan "B" then,
I am fitting an additional power socket in the "trunk" so I will run an ignition switched live for that,  and a fixed live for the trunk light at the same time.

Keep well

Paul