Wiper Blades won't work (Disco 1 and 2)
Every once in a while the wiper blades will fail to work. First pop the plastic trim off the base of the wiper arm (D2 only). Use a 13mm socket to make sure the nut is tight, holding the arm to the operating bolt. Most of the time this is the problem. If one arm is moving and the other isn't make sure the one that is not moving is tight. If both are tight and only one or neither is moving you have damaged the wiper motor cross member or the motor. Your best bet is to buy a used one off someone parting out a vehicle or one of our trusted parts guys like Will Tillery or Paul Grant. New will run you $180 for the entire aseembly.
Make sure to remove all ice from the wipers before turning them on to prevent damage to the motor.
D1 wiper arms are direct bolt on replacements for D2's. This comes in handy when needing to replace the blades as D2 blades can only be purchased from the dealer where D1 arms can fit any standard 18" (front) or 14" (rear) blades.
NELRC reccomends Bosch Icon blades for year round durability, they are made of silicon and will last for 5 years plus and only need an occaisonal wipe to clean them.