R129 soft top.... Help needed !

[sye73]

After returning from a drive out with my roof down, I went thru the normal 'hood-up' routine, only for it to stop half way.Both of the electric windows are not working either. Does anyone have any ideas as to what it might be ? ( I have checked the fuses in the boot area and all seen ok ).
Thanks for any help....

 

[janner]

Soft top controller under the base of the back seat on the driver's side.
Brace yourself, because they're about a grand new.
If you read off the part number you can try the breakers but it's a common failure part so they're hard to find.
Part numbers 129 820 39 26 and 129 820 31 26 are interchangeable if that helps.

 

[sye73]

thanks janner
I tried it again one last time yesterday night and it worked fine ! Do you know if they tend to fail completely, or do they intially become temperamental before expiring ?
There was a 'clicking' noise coming from the unit aswell.....

 

[stats007]

I very much doubt the controller has failed - I have only ever heard of one case where this has happened. The units are sensitive to voltage and also pressure / heat within the hydraulics - the system will shut down for protection. You might want to check for any leaks - the windscreen pillars on earlier cars are prone to failure and the battery voltage. Had you driven the car recently?

 

[sye73]

Thanks stats007 : It looks like you might have hit the nail on the head as although the car has been used recently, I have had some hi-fi equiptment installed. Maybe the heat and / or voltage draw from the amps is causing the controller problems.
With reference to the unit's 'shut-down' feature, is there a normal reset time before all is ok again ?
Thanks for your thoughts.....

 

[stats007]

From memory it is two minutes with the key out of the ignition. Similarly it will automatically shut down after 5 attempts at opening / closing.

 

[sye73]

understood, thanks.
One last question ; Do you know if they 'click' whilst in operation, or are they completely silent?

 

[stats007]

Does what click? The solenoids you mean? Obviously the roof latches make a fair racket!

 

[LeaUK]

sys73

If your windows don't go all the way down and depress the individual switches at the bottom of travel your roof will stop half way. This is the normal mechanism for ensuring the windows are down before the top completes its procedure.

You must resolve the window issue first as this is your clue.

Check fuses under bonnet (hood) and boot (trunk) ;-)

Lea

 

[rajinder_1]

I had similar prob with SL320 01 model, it was a 15 min trip but was scorching so put roof down got back and got stuck half way..... put it back and got stuck further back.
Put it fully back and took key out for few mins and when i repeated it wiorked ok, apparently there is some sensors which tell the car that windows are down and these have rubber which expands in the heat which makes the car think the windos are not down.....thus making the roof stop

Raj

 

[sye73]

Does what click? The solenoids you mean? Obviously the roof latches make a fair racket!

No, not the latches etc..... The clicking is coming from the actual silver control unit located under the rear seats. Not sure if you'd hear it with the seat in situ, but it is noticeable with them removed

 

[stats007]

That's fine - they're the relays to switch power. I'm trying to organise a technical day through the MBOC for the R129 roof as it has some 45 hydraulic lines, 11 solenoids and 15 hydraulic cylinders. I don't know anyone that understands it completely and that includes MB service staff.

 

[sye73]

sys73

If your windows don't go all the way down and depress the individual switches at the bottom of travel your roof will stop half way. This is the normal mechanism for ensuring the windows are down before the top completes its procedure.

You must resolve the window issue first as this is your clue.

Check fuses under bonnet (hood) and boot (trunk) ;-)

Lea

Thanks Lea....
Both of my windows were working perfectly ( both in normal operation and also as part of the roof opening and closing sequence ) until the soft top got stuck half way up. I also checked all of my fuses, as this is often the easiest thing to check first !!

 

[sye73]

That's fine - they're the relays to switch power. I'm trying to organise a technical day through the MBOC for the R129 roof as it has some 45 hydraulic lines, 11 solenoids and 15 hydraulic cylinders. I don't know anyone that understands it completely and that includes MB service staff.

Good, that's a relief ! I was hoping some kind of noise whilst in operation was ok
Hmm, sounds like the techy day would be a good idea !!!!

 

[sye73]

I had similar prob with SL320 01 model, it was a 15 min trip but was scorching so put roof down got back and got stuck half way..... put it back and got stuck further back.
Put it fully back and took key out for few mins and when i repeated it wiorked ok, apparently there is some sensors which tell the car that windows are down and these have rubber which expands in the heat which makes the car think the windos are not down.....thus making the roof stop

Raj

Thanks Raj.
I also tried the ' remove-key-from-the-ignition ' trick, but it didn't work for me! I gave up trying to suss it all out on saturday evening, tried twice on sunday lunch time ( still nothing ), then tried one last time sunday night and all was fine !!

 

[LeaUK]

I still wouldn't mind betting it's the window limit switches (or one of them). If the soft-top controller doesn't receive windows closed position from both sensors it will prevent the top from closing - it may also stop the windows working normally but I'm not sure. Happened to me.