I've been looking at replacing a couple of A/C components in my 91 and see where some places selling driers, evaporator cores etc for "factory" and "dealer" installed a/c systems. I know that some Fords (all models) used to come with a button (with a blue light) that would need to be pushed in order to turn the a/c on. Mine does not have that button, and never did. Just works through the settings on the control panel. Since mine is pretty much optioned out for the model year, my guess is that it's "factory" a/c? Any help would be appreciated.