Do you have the layout of the fuse panel? The Power Moon Roof wire is purple / black and it is in place in the connector (most likely it was in my 95) wether you have a Moon Roof or not. I found it on top of the interior fuse panel in connector #298 pin#8. This is coming from the Power window fuse #21 / 40 amp. You may want to put an inline fuse on your tap wire with a lower amp rating in order to supply proper protection to what ever you are installing. There are several other wires that can be used depending on what options you have, or don't have would be better put.
I would strongly suggest if you don't have the ford cd. You can get one from ebay it has been an immense help to me in adding options that detroit forgot to install like power windows, seats, fog lights, power antenna, and heated mirrors to mention a few. The cd covers the mechanical and service aspects too.
Hope this helps......