Heater, air cond. and blower motor do not run. all fuses are good . cond. runs with jumpers. this truck has the electronic controls and i cannot find any electricl prints to work with. not even chilton. the control panel shows the blower is running but its not. the only thing that seems to work are the lights on the control panel and the 3 fan relays.

SOURCE: 2004 Chevrolet Silverado Heater/AC Blower on without Ignition ON

there is no relay for the heater fan it's a 15 amp fuse and is on the accessories circuit. the reostat is responsible for all 3 speeds .with the key off there should be no voltage to the blower motor whether the fans speed fan switch is on or off. the fuse will be located in the fuse paneleither on the drivers left side in the dash or underneath the dash in the fuse block. you have a short in the harness that is under the dash and most likely it's a bad plug on the harness. your going to have to do some searching but that's where the problem short is... please rate

SOURCE: cooling fan

Whoever told you the temperature gauge on cavalier is normal 3/4th is the lie. It is however in operating temperature range but on the hot side. Have you flushed your coolant and replaced thermostate, and gotten air vapor locks out.

SOURCE: Blower Fan will not blow, we have already replaced Heater Control

you need to replace the fan ...its under the hood on the passenger side held in bt 3 screws and one plug this is the only motor on that side of the vehicle and only takes a half hour to change out

SOURCE: I have an Nissan Altima 2002 with an manuel heater

You also need a computer box and the related servos for it to work.

SOURCE: 2004 Suburban rear blower motor not working !

You will have a blower motor resistor that controls power and the speeds to the blower motor it will be by the blower motor and is cheap new.