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Porsche 993: Why Won't My Top Move When I Press the Switch?

There are many things that could cause your convertible top to get stuck. Here are a few possible reasons why.

By Jerry Perez - April 23, 2015

This article applies to the Porsche Carrera 993 Cabriolet (1993-1998).

You've had the roof down on your Porsche 993 for a while, but the top wont move. The mechanism that operates the roof contains a lot of moving parts, so there could be more than one reason why it's not moving. You can always take it to the dealer, but if you can troubleshoot this yourself, you'll save a few dollars.

Step 1 – Check the fuses

Fuse boxes provide a controlled electrical supply to the desired component. So, when electrical gizmos happen, they are stopped by the fuses. The fuse box is located in the trunk right above the shock mount. Use the diagram on the lid to find the correct fuse, and make sure it is not burnt out. If this is the problem, then it's an easy fix; if it's not, then proceed to Step 2.

Figure 1. Fuse box.

Step 2 – Check the control unit

The convertible top control unit is an electronic box that controls the operation of the convertible top. It includes multiple connectors on an electronic board. First, check to make sure there aren't any loose connectors plugged in to its side. If there aren't, then check for any cracks or bad solder spots. You can tell by inspecting any spotting or dark areas around them (compare to the rest). If this causes the problem, then you'll need a soldering iron. If that doesn't fix it, then proceed to Step 3.

Figure 2. Convertible top control unit.

Step 3 – Check the parking brake sensor

It could be telling the car isn't engaged when it is.

The Porsche 993 requires the handbrake to be engaged in order for the top to operate, but there is a copper connection located inside the boot of the handle that dictates the position. Sometimes it just happens to be loose, so wiggle it and make sure it has a firm connection. If not, then replace the connector.

Figure 3. Copper connector in handbrake.

Step 4 – Are there any physical blockages?

There might be something blocking the mechanism.

While it's not very common, sometimes the easiest solution to a problem is the most basic one. Make sure you manually retract the top and check its surroundings. Check the storage compartment where the top folds up, along with the sides where the metal arms fold and bend. If anything is in the way, remove it.

Figure 4. Make sure there are no foreign objects blocking the roof mechanism.

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