Yes, to remove the dash assembly from your '66 Chevy C-10 pick-up you have to remove the windsheild. You should find four more screws that are under the gasket. You will also have to drill out about 12 to 14 spot welds that are holding the dash to the fire wall. I just finished taking my dash out and it took about two hours, with help. Good luck with your project, it's worth the effort. Replacing the dash is much easier than taking it out. www.frontlinebody.com
Remove the black cap at base, remove nut, then gently pry up from under the arm this can be a pain but be careful the splines are made to strip to avoid damage to the transmission arms.
under the hood by the engine
The wiper motor is located under the black plastic cowl below the windshield.
You'll need to figure out where the water is coming from...the gasket around the windshield can fail, if you have a sunroof I'd start there, maybe the side windows rubber gasket or even the gasket around the doors. It all begins with where does it come from. BTW: If its green and under the glove box, I'd check the heater core.
It is located under the windshield cowl (the plastic cover with the holes in it, directly under the windshield). To expose it - remove the wiper arms, and the retaining nuts on the wiper shafts, then remove the screws holding down the cover.
Remove the old filter and make sure you remove the old gasket, there should only be 1 gasket.
They are located under the air inlet grill directly in front of the windshield. You have to remove the wiper arms and antenna to remove the grill.
The windshield washer pump is in the middle on the reservoir right under the hood. and you need no tools to change it.
The motors, both for the front and the rear, are located at the very bottom of the windshield wiper fluid reservoir. To gain access to them, you have to remove the battery and the battery plate, along with several other bolts that you gain access to from under the car.
you have to remove the cowl panel under the windshield. it is attached with several screws
Under the hood, on the firewall, drivers side.
The wiper motor on a 1998 Chevy Venture is up under the vents next to the windshield. It is bolted to the firewall.