Blower Motor Resistors - 2001 Chevy Venture
There have been MANY posts in the forums about
the blower for the A/C or heater not working on one or more settings (only
works on high, etc.) In most modern vehicles, the
Blower Motor Resistors control the
speed of the blower.
Here is some information I gathered from a couple of repair manuals that
might help in troubleshooting and repairing
any problems that you might have with your blower motor speed related
Blower Motor System - Description &
The blower system
for the AC or heater includes the following major components:
- The Blower Motor itself
- The Switch
- Three (3) fuses.
Two are in the
Fuse panel (inside passenger compartment): fuse #28 & fuse #46. The
other fuse is in the under-hood fuse block, fuse # 29.
- One (1) Circuit Breaker (#5 -
inside passenger compartment), which is used in High Speed mode
- The Blower Motor Resistor Assembly
- All associated wiring & connectors (see schematic below).
Power for the blower is supplied
through the HVAC Blower Fuse (#28) and is sent to the blower speed
switch. As the switch is moved from setting 1 through 5, more current
is allowed to flow through the motor, for a higher speed. This
is because less resistors are in the path as the switch is moved to a
When the switch is on setting 5
(High), all resistors are bypassed and a relay on the resistor pack is
turned on. This provides power (12 volts) directly to the motor,
through a circuit breaker.
- The blower motor resistor assembly
is mounted next to the blower motor, inside the HVAC module. This
is so that air will flow across the module to help keep it cool (it
can get very hot).
- If one of the resistors burns up
(opens), only a few of the speed settings will work.
Here is the schematic for the Blower Motor Resistors
and the blower system. Click on it for a larger view.
Van Home |
Maintenance Index |
Other Information |