I have attached a picture of the meter I am using. If the LCD screen is the top of the meter, I am using the top left function to check voltage from the head unit when it is turned on. Off, there is no reading, ON it reads around 13 with the original surge, then it stays around 5. The Ohm function I believe is the bottom left and when the vehicle is off, it will jump up to about 150...

 

The blower motor is a variable speed unit, with 4 speeds. Full battery voltage is supplied to the blower, however when the speed controller is changed the unit is grounded through the resistor pack in different paths, resulting in different voltages at the blower motor. At the highest blower setting, the voltage at the motor should be the same as the battery. You can use power drawn directly from the battery to confirm the function of the blower. If it works fine, then you need to look either at the controller or the resistor pack. You could try bypassing the resistor pack to see if you can get the controller to make the blower spin at full speed

 

5 volts is not enough to run the motor. You need to bench test it, as has been suggested. I repaired my situation by following a thread on a different forum about bypassing the under dash fuse panel for the blower motor circuit and installing an in-line fuse.
Good luck!

 

There's a speed control resistor mounted in the heater fan box that drops the voltage through a couple of resistors to give you different speeds depending on switch position.

If you have 5 volts going to the fan, that means that both the fan and the resistor have continuity. If the fan doesn't spin, it's bad.

The resistor has a solder link in it that's designed to open up if the temperature in the heater box or the motor current gets too high. If it does open, you can solder it back, but you'll need to address the problem.

Sounds like a bad fan motor though. How easily does it spin? 5 volts should run it.

 

Actually, if this is a D2, there can be a device called the power transistor between the source of 12 volts (the head unit) and the motor. It has I believe 40 different power levels. No longer a resistor pack for four speeds. Break out the RAVE circuits manual, page 78 of 152.

 

The RAVE I have lists it as a 4 speed with the grounds through a resistor pack, and shows the resistor mounted behind the glovebox. The control panel it shows is the manual one that has the rotary switches. Does the version we have in the States have the resistor pack replaced by a power transistor? That would make sense. The auto HVAC controller in the P38 used a power transistor as well. I had one fail on my P38, but when they fail the blower motor will run at full speed only. Sounds like the issue here is the motor. If you pull 12 volts off the battery and test the blower, it will tell you if it works or not.

 

Well, I checked in my files for 2000 and 2003 and saw this. The power transistor is located next to the fan, so will be easy to see. Pages attached. Perhaps this would apply if you have the AC control that does not have the old style rotary *****.

 

Ok, so I spliced some wires on to the motor wires and hooked them directly to the battery, the motor spun immediately. I checked the voltage again at the power feed under the dash. It fluctuates from around 10 to 15 volts, depending on the speed. When the unit is off, it also registers continuity at the motor connector. Is there a relay I'm missing? All my fuses are still in working order...

 

Does your AC control have a digital display with buttons, or a series of ***** and a slide switch for the fan?

 

The Unit is digital.