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.
1991 Chevy s10 how to replace outside window weather strip
No it will not SORRY.
Hydraulic.
5x4.75
No it does not. Chevy did not use them in that year on there trucks.
Cannot unlock steering wheel on 1991 S10 Chevy blazer.
in the gas tank
It is in the throttle body.
Haynes makes a manual with the wiring schematic for the O2 sensor on a 1991 Chevy Blazer S10. The manual can be found at most book stores.
check for vacuum leaks that wull usually cause this problem
4X10's
Unbolt it from inside, lift it out.