W126 1986 560SEL Sunroof Tilts Only - No Retraction

[Golden80s]

Hello All,

Bit of a strange fault with my 1986 560SEL’s sunroof.

It will only "tilt up" and return back down to "fully closed" - it simply refuses to retract.

Before this abrupt and sudden failure the sunroof was operating flawlessly.

The cable, gear, and motor, all sound very good and smooth as they move freely through the retraction (fully open) and return (fully closed) cycle stopping when they should - it is just that the sunroof panel doesn’t move one bit the entire time.

If I abort fore or aft movement at any intermediate point during the open/close cycle and then press the switch for "tilt up" it first cycles absolutely normally (by the sound of things at least) to the "fully closed" stop position and tilts up from there just as it should.

What it the world could be going on here?

Thanks in advance for any insight into this that you might have!