Unplug the sockets and check the sockets for water and corrosion. If the fuse still blows with the sockets unplugged, then troubleshoot the wires themselves.
This could be simply a 'bad' dimmer control.
Good improvisation. Blower should work on high speed with DEFROST selected (leftmost button) regardless of engine temperature. Let us know if DEFROST does not work also. Could be ACC fuse, blower fuse, or bad ACC.
Does the cabin courtesy lamp dim when you switch on? If one or two plugs are out, the indicator may not light, but the lamp may dim, indicating that the other plugs are trying. Wait a good 30 seconds to let any remaining plugs get as hot as possible. To check plugs, unplug the glowplug harness from relay box on/near left front inner fender in engine compartment, use an ohmmeter to check resistance of each to ground. Should be less than 1-2 ohms. Also, check resistance of strip fuse under philips screw terminals on top of relay, if it's 'blown' plugs cannot glow.
Check both sides of each fuse with a voltmeter of trouble light, to be sure the fuse isn't cracked. Replace them all if you like.
Does the cabin courtesy lamp dim when the window switch is acivated? If it is mechanically stuck, the motor will draw current and dim the light. Otherwise, it's likely a bad switch contact or broken wire.
My suggested priorities:
1. Engine start/glow plugs. Don't use any more starter fluid than you ABSOLUTELY need to...
2. Side marker lights. Avoid "Officer Friendly" stopping you to inform you that your lights are out.
3. Air Conditioning Control (ACC) since it involves your comfort, and Defrost involves safety.
4. Windows.
Let us know how you progress
Best Regards,
Jim