Help! Mercedes Technician needs Porsche Guidance!
 

Hello all,

I am a Mercedes technician who is attempting to repair my sister's '97 Boxster. The convertible top motor on the left side is rotating and raising the left side of the top, however, the right side motor is not moving at all, causing the top to twist. A few questions......

Do these motors typically fail? Is there a seperate relay for each side motor?
Also, to replace the motor if that is the failure, do any of the interior panels have to come off to remove and replace it?

I appreciate any help! And if any of you may have Mercedes questions, please feel free to ask!

Thank you,

Tony

Not sure on the relays but there is a small wire cable that operated each side, the older units had plastic ends that break off, it could be that both motors are fine and you have a broken actuator cable. If that is the case, there is a procedure you will have to follow to reset the timing cycle correctly. Try the search feature, I think I have seen instructions and pics in here before, good luck.

This link might help...
http://www.renntech.org/forums/index.php?showtopic=68

If one side raises, it's not the motor.

A single motor drives 2 transmissions (Lft, Rht) via a dedicated drive cable to each. The Transmission in turn raises/lowers both the Top Lid links and 2 push rods @.

The likely culprit is the drive cable. Another likely suspect might be the transmission itself.

Access the area and swap drive cables. Hook to a portable drill and see if the transmission now drives the assembly. If so, it's the drive cable. If not, it's the transmission.

Each has been known to fail. The square-end Drive Cable ends round-off with time and can no longer be turned by the motor. And the Transmission's internal gears can strip.

Whichever part it is, once replaced, the whole top assembly (both sides) will need to be simultaneously synchronized.

Care should be taken whenever operating this assembly until fully synchronized because damage to the Top Lid (Convertible Cover, Tonneau, whatever you want to call it) can easily result.

There are plastic end links on the Top Bow push rods (not the Drive Cables as erroneously mentioned), and these do break. But, if it were the Push Rods, the Top Lid would still function, though likely be damaged.

Aftermarket push rods are available with metal end links. But, the OEM end links are designed in plastic specifically to break first rather than bend or tweak the frame members. Personally, I would not switch to the aftermarket metal ones.

The OEM push rods can break simply from fatigue causing great frustration and hence the appeal of the ones with metal end links.

But, if using the metal ones, you're going to damage the Top Frame eventually, and this is a more complex and expensive repair than simply replacing the push rods.

Thank you!
 

Thank you all for your help! I appreciate all of the information. Thank you very much!!

Tony

I've done this repair on a 98. The problem is the housings for the cables (Porsche has issued a Tech Bulletin and cars from 00 on have an updated cable housing and transmission). Unfortunately, the cables do not easily disassemble from the transmissions. The trouble with the early housings is that they are unreinforced plastic, and after time, tend to stretch. This pulls the inner cable out of the motor. The DIY fix is to shorten the housings by 1/4 -1/2 of an inch.