I have a 1999 Tahoe. The high speed (only) stopped working. I replaced the blower switch and the blower relay. I checked the voltages and continuity between the various components and all seem ok though I do not have a wiring diagram to be sure. The voltage (purple wire) to the blower increases as the speed selecter is switched from low to high while connected to the blower except at max blower speed the voltage at the blower is zero. However when this same wire is disconnected from the blower the voltage to ground is ~12 volts at all four blower switch speed positions including max speed. There is no evidence of any over heating or corrosion of any connections or wires. I have detailed voltages at all of the various components/terminals versus the four blower switch positions if that is useful.
Since the blower runs fine at all but the max speed I am assuming it is not the pproblem. I only see two wires to the blower 1.) the purple power wire and 2.) the black ground wire. I am at a loss as to what is wrong. Any help is appreciated.
Thanks
Since the blower runs fine at all but the max speed I am assuming it is not the pproblem. I only see two wires to the blower 1.) the purple power wire and 2.) the black ground wire. I am at a loss as to what is wrong. Any help is appreciated.
Thanks
