I recently added automatic window down to several of our 700/900 cars. The first thing to do is get the automatic window down relay and associated wiring from a 1995+ 960 or S90. I'm sure the automatic window relays from other cars can be used, but I used the 960/S90 relay. Pictured below is the relay and wiring from a 960.

The gray connector goes to the window motor, but the connector won't mate with the 740/940 connector, so you'll have to make a butt splice. The yellow/red wires and the black are spiced into the same color wire at the switch. See below.

The picture below shows the butt spices for the motor wiring.

The next picture shows shows a neat place to install the relay.

The auto down functions works nicely. If I had the auto up and down relay from a later car, I'd probably install it. The auto window up functions I have tested have a reversing feature. If the window is blocked on the way up, it will stop and go all the way down.
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john
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