I will post and not cover Rear AUX heater box. ok, and is and option
what part of this car has blower
is this
HVAC blower failing on HIGH
is this manual version or climate control option.
fuse are blown in cab or in bay (engine)
fuses are first of high speed blower mode fails dead.
what IS A CKED ????? is see no hits in my ASE books on that part or device name in a car or a truck
2003 chevy tahoe , no engine /trans told. (this dictates fuse boxes)
my guess HVAC topic but no sure, what fan/blower or turbo this is.
climate control model has left and right controls and all differenet wiring max. differ.
fuse Hvac1, hvac-ECas, and fuse BOWER< yes 3 fuse must not be blown and the BCM is the brain here.
not scanning the PCM to see BCM errors is a huge error in testing
manual controls the resistor block uses a relay to send 12dc to he blower set to HIGH. all resistors bad ,high still works.
here are the 4 things to fail;
4 is good so 3 things, 2 fuses,
#3 is relay. to fail. a volt meter finds this easy for sure reading this page in the SM.below 3 pins on relay are at 12v.
so are pin F and G 12vdc if not input to them is bad.
not counting bad wires.,