The blower located behind the glove box only operates on high speed. It doesn't matter if the control is in heating or cooling. I swapped out the speed controller with another and no change. Also, the ac pilot light only lights up when the blower is on high speed. I unplugged the blower and measured the voltage to be 13.5 volts regardless of the speed selector switch position. I also noticed if the blower is unplugged, the ac pilot light lights up on all the speed settings. The high speed only issue was a sudden change, not a gradual change. Any thoughts or ideas would be greatly appreciated. DodgeInLaw

 

probably need new blower resistor block or wiring to resistor block

 

No other speeds work. High speed only on either hot or cold temperatures. DodgeInLaw

 

idk what difference the temp makes on blower operation??? if you only got high speed then you probably have an electrical problem with the device that controls voltage to the blower for lower speeds. so you probably want to have someone with electrical diagnostic skills and tools test the resistor block first. a wiring diagram would be pretty handy at this point

 

Ck at the top of the page in the tizzy DIY, there some wiring diagrams there or ck on the other post with A/C problems.