Originally Posted by Best4x4

If you have the lower dash cover off, you’ll be staring straight at the blower. It has a blue 2pin connector. Now off to the right of the blower and usually held onto the blower pack assembly itself is another 2pin connector, this one is white/off white. One side goes into a harness up to the blower relay, and the other side if I’m not mistaken leads to the blue 2pin on the blower or the resistor.

Check it & chances are it’s melted & not causing a good contact.

Originally Posted by Twix

The fuse panel going is actually quite common. Moisture gets in and corrodes the boards and stuff will at first intermittently work, then just not work altogether.

My motor would spin, then shut off then on again. Eventually it just crapped out. I checked the fuse and it was fine, the transistor pack rarely has issues since it's solid state. Checked for power at the motor connectors and had nothing, while sometimes it would show up.

So start with power at the motor lead connector? Do you have 12v there? If your fan needs a bump to start directly off the battery, it's done. Needs to be replaced. It should spin at max speed and accelerate to that speed within 2 seconds of having 12v supply. Speed controller isn't a resistor, it's a solid state transistor power supply. Chances of it crapping out are close to zero. To test, try cycling through fan speeds, you'll see voltage change at the motor leads. Check for voltage at the fuse as well, I'd actually start here. If there's no voltage across the fuse holder then you won't have power at the motor.

Keep in mind one thing. My panel was toast but would give me voltage readings across the fuse. But once there was a load attached, the board would open and the connection and voltage would be lost. I eliminated all the other parts one by one until I found the fuse panel boards would open under load.

1. Check fuse
2. Check fuse for voltage across the holder
3. Check for voltage at the motor lead connector (if it's brown it needs to be fixed, common)
4. Check motor directly to a 12v source, should spin hard and fast almost immediately

Lastly, make sure if there is voltage at the leads, to cycle through the fan speeds to check for the power pack operation.

Let me know what you find.

Originally Posted by Extinct

I would also suggest the underdash fuse box, drivers side. The blower fuse connect suffers from a cracked solder connection. Some people take the fusebox apart and resolder, some replace it, some bypass it by connecting an inline fuse to the input and output wire. Look for the threads on blower fuse.

Originally Posted by Best4x4

Glad it's working and I'm glad the wiring harness didn't look like the 03 500.00 D2 I have. I've always felt like the max speed on the D2 blower was on the weak side vs other vehicles. There is a mod for a Pontiac blower someone did in a D2, but I don't have that info saved.

Originally Posted by Twix

So with the motor disconnected from the connector, you can check the voltages at the pins as you work through the speeds.

Voltage should vary from ~12v at full speed to maybe 8v at it's lowest (not entirely sure, but it will be lower)

Edit: looks like it's all working in that video, but I still suspect that one or more of the speed control or power connectors isn't fully engaging.

Originally Posted by Twix

Another thing I forgot to ask, what vents are you trying to get air out of? Have you tried cycling through all the various vent combos to see if air is coming out of all the vents? With the fan in the off position, you should be able to hear the mixers moving.