Sounds like you have the dreaded Mark VII system? Or at least one thats similar?? The WEEPER solenoids you refer to shuts weep water off to a bay foam brush to keep from diluting the mixture when in use...Or at least thats how Mark VII designed their system...These valves are NO (Normally Open) meaning they are open when no power is applied....When power is applied they close. If you replaced them all, did you replace them with the right ones, normally open? If you replaced all the valves with NC (normally closed), that makes sense why you are freezing up! Let us know if this is the system you have?
If this is the type system you have, the solenoids you refer to are or should be totally seperate from a single weep solenoid that supplies weep for all bays. On My Mark VII, in the beginning, I did away with the individual solenoids and used methanol foam brush
soap...Now I use a washer fluid/air injection system that winterizes the foam brushes and foam guns below 32°....Weep water is way too expensive where I live to throw it down the drain!