Therefore, to refill the rear washer fluid, you simply need to refill the main windshield washer fluid reservoir. This is usually located under the hood, often a translucent plastic bottle. Locate the reservoir (check your owner's manual if you have trouble finding it), and add washer fluid until it's full. The rear wiper will then use fluid from this same reservoir.
If, for some reason, your Explorer *does* have a separate rear washer fluid reservoir (this is less common but possible), you'll need to consult your owner's manual for its location. The manual will have diagrams and descriptions of all fluid reservoirs.
