Land Rover Repair: AC Blower Motors wont run, land rover discovery, wiring books

Question
1999 Land Rover Discovery and niether front or rear blower motor will run.  I checked all the AC fuses inside and under the hood.  I also unplugged the front blower motor and put a volt meter to the two wires and found the voltage changed from 11.6 to about 13.4 when cycling the control speed switch from low to high. All looks good on the panel.  I then pulled the front blower motor and jumpered it with 12 volts and it ran like crazy.  I put it back in and neither worked still.  I disconnected the battery and left it off hoping it might reset but it didn't work either. I looked at the suction side of the lines to the compressors and they are sweating and the clutch is staying engaged. I even jacked the temp. up and put on defrost and nothing still ran. What should I be looking for as to why neither blower motor will run?

Answer
If your statements are all correct then you have a failed blower control unit, or a wiring fault.  The next step is to take the wiring diagram and follow the circuit from the fuse board to the climate control panel, to the blower to find out where power flow is lost.  If yo do not have a wiring book you can buy the print version from vendors like Atlantic British or Rovers North.  You can also access the wiring books online for a small fee from Land Rover's official site, www.landrovertechinfo.com

Best wishes
John