I wanted to share a technique I used to test my power window motor. I figured it was best to start at the motor and work my way back. Here's a quick video of how to get access to the motor:


You can now see the power window motor through the hole in the door panel:


Power window motor is now visible

I have found that a WiFi Endoscope Camera is very helpful for inspecting tight spaces on the Porsche. The one I used here was purchased from Amazon for less than $40:


I have also used this camera to inspect the fuel tank and engine valves

Here's the connection to the window motor that I found with the camera:


Reversing polarity of 12V to these connections will move the window up and down.

Next I used spring loaded test leads to attach to the window motor's positive and negative posts:


Here's what the test setup looks like with both test probes attached to the power window motor:


I used a 12V jump box as a power source to move the window up and down by reversing the polarity.

I hope this technique is helpful to others diagnosing power window problems. Please let me know if you have questions or other techniques.

 

Very nifty technique. I think I would just pull the whole door panel to have wider access and visibility. You sure seem to get the job of testing the motor done, with the minimal fuss.
Thanks,
Dave

 

That's a cool little camera. I keep a spare pigtail I yanked from a parts donor many years ago. I cut the wires back about 12" so that I have plenty of room to easily reach the wires with the jump box. Incredibly handy when pulling the door glass with the door removed. Removing the door card would be a big advantage. Five more minutes and you're there. If there is an issue with the motor, regulator, guides, etc. then you're that much further ahead.

 

On this 1980 928s Euro, the door panel was glued to the door frame and I was worried about damaging the panel during removal. This may have been done by the previous owner..... Have others come across glued door panels?

 

Fortunately, no. Next time the job makes it necessity to pull the door card see how much of the glue can be cut with a sharp putty knife. Surely they didn't use a two-part structural glue or something else along that composition. Maybe it won't be a big deal. However, whatever reason it was that they glued to begin with may reveal itself as a trickier correction project.