Originally Posted by jwikoff99
no prob acg...
Now just for my clarification, was the round thing you were talking about actually to the left of the master cylinder, or mounted between the cylinder and the firewall? If it is attached to the master cylinder, it is part of the brakes, if it is not and is about a foot to the left, it is the blower motor for the climate control.
Okay, the large round thing mounted between the master cylinder and the firewall is the vacuum booster for the master cylinder.
Inboard of that (i.e. moving towards the passenger'* side) along the firewall is the large, cube-shaped vacuum reservoir for the ventilation system controls. On older cars (i.e. 1980s and earlier) it'* a plastic sphere mounted near the right-side hood hinge, but not on these Bonnevilles.
Almost in the center of the firewall and a bit lower down is the blower motor, installed in the heater/evaporator core housing. It'* round, about 10" in diameter with five mounting screws and a rubber cooling duct coming out the side (unless this is my car, in which case the cooling duct is missing.
The core housing extends towards the passenger'* side from there, and the blower motor resistor pack (for cars with C61 manual climate controls) or the electronic blower control (for C68 electronic systems) installs in the top side of the core housing, below the middle of the "Maxifuse Relay Center" containing fuses and relays on the firewall.