W124 - Weird traits with boot open

[Vectrolosys]

Hello,

This problem relates to a 1991 (August 91 registered) W124 300TE.

If you have the interior light switch on the dash, set to the 'come on with the rear doors and boot open' position, you'll get a strange buzzing from behind the dash (which sounds like a slightly strangled lights on buzzer), the dash tell tail lights, and number plate illumination lights will all illuminate.

This says that something is shorting somewhere. Is it possible that there is a short in the wiring going into the bootlid?

Thanks for any advice,

James

 

[nick mercedes]

Hello,

This problem relates to a 1991 (August 91 registered) W124 300TE.

If you have the interior light switch on the dash, set to the 'come on with the rear doors and boot open' position, you'll get a strange buzzing from behind the dash (which sounds like a slightly strangled lights on buzzer), the dash tell tail lights, and number plate illumination lights will all illuminate.

This says that something is shorting somewhere. Is it possible that there is a short in the wiring going into the bootlid?

Thanks for any advice,

James

Sometimes the wires in the boot hinges get a bit fraid?

 

[Vectrolosys]

Sometimes the wires in the boot hinges get a bit fraid?

Funnily enough, I've just read that somewhere else. Would make sense from what I have been reading. Looks like I'll be stripping the wiring down and checking it over

 

[Smiley]

My w124 does exactly the same. I have tracked the problem to the wiring where it goes into the roof at the top of the tailgate - it goes brittle here and cracks. It is not easy to fix unfortunately as it is a bu**er to get the roof lining out and remove the internal connections of the wiring to give enough slack in the wiring to fix it.
So I am afraid to confess that I went for the simple fix and turned the dash switch to the centre off position.
If you figure out a quicker way to fix then pls let me know!
Just out of interest check your number plate bulbs when lifting the tailgate - mine work fine with the tailgate closed - then as it is lifted they go out - another strange symptom of the wiring problem.

The saloons suffer from the same problem - the wires going to the number plate lights go brittle and crack and short - but there the symptoms are limited to the exterior bulbs.

 

[Vectrolosys]

My w124 does exactly the same. I have tracked the problem to the wiring where it goes into the roof at the top of the tailgate - it goes brittle here and cracks. It is not easy to fix unfortunately as it is a bu**er to get the roof lining out and remove the internal connections of the wiring to give enough slack in the wiring to fix it.
So I am afraid to confess that I went for the simple fix and turned the dash switch to the centre off position.
If you figure out a quicker way to fix then pls let me know!
Just out of interest check your number plate bulbs when lifting the tailgate - mine work fine with the tailgate closed - then as it is lifted they go out - another strange symptom of the wiring problem.

The saloons suffer from the same problem - the wires going to the number plate lights go brittle and crack and short - but there the symptoms are limited to the exterior bulbs.

Funnily enough, that's the route I have taken!! I'm going to have a poke around, but not until later in the summer as my wife is due with our second at any time now.

I had a feeling it would be around the hinge area though, it looks ripe for problems later in life, what with all the movement it has to endure.

I'm popping out in a bit to give it a wash and polish, and check the bulbs over, so will have a look and let you know.

 

[Vectrolosys]

Hello,

Yep, when I lift the bootlid, with the lights on, the numberplate lights go out.

I managed to remove the trim panel at the rear of the roof, and can see all of the wires in here, however, I haven't attempted to remove any further than this. There is a large wiring block on the passenger side of the car, that has a spur coming off and into the bootlid. I am tempted to work out which one goes where, then run my own wiring loom into the boot lid and down to the various areas it needs to go to. Bit intense, but could be the only way forward.

James

 

[daveaston]

I'm the new owner of this car, and experienced all the above problems, so I decided to see if I could fix them.

First off, downloaded some of the wiring diagrams from here: Model 124 Maintanence Manaul Index

Had a good look at them, and full of confidence, decided to strip the old loom out of the tailgate to see if it was chafed.

Got inside the headlining to find the junction block, all the wires nicely numbered, so disconnected the tailgate loom and pulled it out for inspection.

Sure enough, where the loom clips to the tailgate hinge, on the left hand side, inside the protective rubber boot (which was still good and intact) three of the wires were severed and three more well split and about to about to be cut too.

I decided not to bodge it up, but made a new loom for it. The multipin plugs unsoldered and swapped over easily enough....got it all refitted today and it all seems to work. Especially good to have the automatic closer and the interior lights working again.

If anyone needs details of exactly how to make the loom, feel free to pm me. Unfortunately its not a quick fix, I guess it took me a day and a half, but next time I could probably do it a bit quicker.

Cheers, Dave

 

[adl]

New Wiring Loom

Thanks for the description - I think I am seeing the same problem and would appreciate seeing your design of the loom and having your advice about the best way of getting behind the headlining to extract and replace the loom!