When the temp goes down to +20F or colder, the wiper fluid doesn't come out. I'm using the -20F fluid. Once the temp goes up to around +30F, everything is fine. Does anyone know if the pump freezes up in the cold?

 

change washer fluid.

ive run the washer -7F with no issue.

 

can check the lines n see if they're frozen n make sure all that's in there's low temp fluid.

 

I installed HotShot which is windshield washer fluid heater on my 09 Honda FIT Sport MUGEN. I got it on eBay during Summer for $47. It works really good. It is the same manufacture that supply this product to GM. It melts snow on my windshield within less than 3 minutes.

Windshield Washer Fluid Heater

 

what happens if/when it freezes in the lines and/or reservoir?

 

Good question but I have not encountered the problem yet. I use anti-freeze washer fluid. I believe that its freezing point is -80 C. Since I live in Maryland so it is unlikely the temperature will be below -80 C.