hey, we are having a get together with our 928 's on the 20th at the pca lapeep restaurant at 730 am then at nine go over to the kcauto museum.....are you in....hope to see you there....there is a thread started on this one....see you there !!
andy

Hi Ed. I'm trying to install a cheap KE system on my '89 S4 and am finding your diagram, with the Sachs 9xx.618.113.01 unit, to be very valuable.
Unfortunately I'm not using the same model of KE system as you diagramed, so I'm wondering if you can explain the relay function/theory in the hatch circuit? I see you appear to be applying 12v to the Yellow wire in the passenger switch when activated. But I don't quite follow the trunk/coils logic in the KE system you selected. My cheapo one only has "Trunk (+)" and "Trunk (-)" so I'll need to suss out exactly what that's doing too. (if it's just supplying voltage or ground I could probably wire the relay as you show but with the signal to ground on one side, then the +12v to Yellow on the high side.)
Does your system work with the doors locked? I've seen some note that they have to unlock doors to use the hatch release.

Thanks in advance for any pointers.