How do you prevent the windshield washer pump and or lines from freezing? Ours freezes even though I ahve added -45 celius fluid and windshield heat additive.

 

If its freezing, plain water or moisture is making its way within the system somehow? There could be a chance you purchased defective Winter Windshield Fluid... try using another brand?
If the problem continue after using another brand, I would suggest trying adding a pint of Isopropyl Alcohol to the mix; this is the kind you find in your local drug store and such?