[R129 SL] 129 Top problems

[Satish Tummala]

Yes, the R129 hydraulic top mechanism is actually quite bulletproof.  On
occasion, the top control unit may fail but the single most common
problem is the resynchronization/out of sync condition.  This, of
course, is easily rectifiable.  The hydraulic unit, although expensive,
rarely fails.  There are several microswitches which help the control
unit determine the position of all the various linkages.  These may be
bad or need adjusting.

Satish


-----Original Message-----
From: r129list-admin@mbcoupes.com [mailto:r129list-admin@mbcoupes.com]
On Behalf Of Norm and Pat Waleke
Sent: Sunday, February 17, 2002 1:46 AM
To: r129list@mbcoupes.com
Subject: Re: [R129 SL] 129 Top problems


on 2/16/02 4:44 PM, Tom and Karen at tandkw@bwn.net wrote:

> While trying to put the softtop down on my 1990 500SL, the whole top 
> mechanism quit working. The rear hard(tonneau) cover went up, the top 
> unlocked and then nothing.  I can put the top down manually even 
> though I can tell it is working against hydraulic pressure. The 
> latches for the hard cover are in the latched position, with the cover

> up.  Fuse #6 under the hood is good. I have power to the fuse block in

> the trunk. The red light in the switch is on steady. I can put the top

> up manually and lock it. Moving the switch only puts the windows down 
> or up.  It seems the whole system is out of sync. This has been a 
> problem ever since I got it home from the dealer(Sears in MPLS), 2 1/2

> years ago. It worked before I bought it, (at least it did once), and 
> then intermittently with help until last year the dealer had it, and 
> now, nothing.
> 
> I have an appointment with the Mercedes zone rep on Monday, which the 
> Denver dealer set up. The dealer had the car for 6 weeks last year and

> didn't get it right. I assume that the top system is so troublefree 
> that dealers never get good at diagnosing/fixing them.
> 
> I am wondering if any other lister has had top problems of this nature

> and what the resolution was.  Thanks in advance.

Tom,

We had a similiar problem on our SL500AE last summer, but it started
with a low battery and the top down. The light also stayed on all the
time. We called the dealer and they told us that the windows and the top
needed to be re-synchronized after having a low battery. That didn't
take care of the problem, so we took the car in and they said they had
never had this problem with any other car, but they finally diagnosed
the problem as a defective 'top control module', which they replaced and
everything works just fine now.

Hope this helps,

Norm and Pat
New Mexico, USA
'89 560SL 42K (his) "White Knight"
'91 Mighty Max 34K (ours) "Blue Max"
'93 300E Sportline 50K (ours) "Green Hornet"
'97 SL500AE 4K (hers) "Red Baron"
'98 SLK230 7K (ours) "Slick"
'00 S2000 2K (his) "Ichibon"
'01 PT Cruiser 2K (ours) "Salsa"
'01 Prowler .5K (hers) "Pumpkin"
photos: http://www.zianet.com/SLlover
SL Gallery: http://www.zianet.com/SLlover/page11a.html


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