Originally Posted by lottje
im havin some what the same issue in my 99 ranger. ac compressor turns on but fan stays off on all settings. All fuses are ok. Read up on a few other things leading to the motor resistor, going to check that tonight if that works I will let you know.
To give full power to the blower, the blower resistor block is completely bypassed on the highest fan setting. If the blower isn't working on high, then your problem shouldn't be related to the resistor block.
It is difficult to diagnose your problem long distance but I would guess that you might need a new blower or a blower relay. However, before you buy any replacement parts, check the plug connector underhood at the blower. Sometimes the pins corrode badly, especially in areas where road salt is used.
If the pins look OK, then check the voltage at the blower connector. With the ignition switch on, the fan switch on the high setting and the mode selector anywhere EXCEPT off, there should be battery voltage across the PK/WH and the OG/BK wires.
If voltage is there, you might suspect a bad blower motor.
If it is not, check the blower relay and trace the wires for opens.