
SOLUTIONCAUSEPROBLEM
NO OPERATION
(1) Low voltage
(2) Blown fuse
(3) Loose power connection
(4) Thermostat not correctly set
Correct power supply – 10.5 VDC Min is
required to operate.
Replace with appropriate 8 amp slow blow
fuse.
Remove garnish ring, check power wire
connections.
Adjust thermostat to a cooler setting.
(5) Vent lid is closed Open vent lid
(6) Vent closed limit switch Adjust or replace switch
No thermostat operation (2) Thermostat circuit board Replace Thermostat Circuit Board
(1) Low voltage Correct power supply – 10.5 VDC Min is
required to operate.
(3) Vent closed limit switch Adjust or replace switch
Fan runs in one direction
only. (Intake and Exhaust
Models)
(1) Rocker Switch wiring Check for loose or broken rocker switch
wires
No Manual dome operation:
(Manual vent models only) (2) Broken gear coupler Replace gear coupler
(1) Broken worm gear Replace worm gear assembly
(3) Broken vent knob Replace knob
Fan Speed
(High speed only)
(1) Resistor pack Replace resistor pack (also check for high
current fan motor 4.5 amps maximum).
(2) Speed selector switch Replace four position rotary switch.
Vent lid motor runs
lid does not open or close
(auto vent opening Maxxfan
models only)
(1) Broken gear (s) Replace vent lid motor
Vent lid motor not running
lid does not open or close (1) Loose plug connection Remove MaxxFan assembly from roof,
check plug connection between circuit board
and lid lifting motor.
(2) Circuit Board Replace circuit board.
Fan runs all the time (1) Thermostat is set to low Raise thermostat setting.
(2) Inside cabin temperature above 115
degrees F. Fan will operate continuously if temperature
is 115 degrees F or higher.
(2) Broken operator gear Replace operator gear assembly
Rev.7.26.05
(2) Rocker Switch Replace rocker switch