You just found the best remedy, a torch. I use a propane one, my brother uses a pocket torch. He keeps one with him all winter. He uses it to thaw locks on his snow mobile trailer too. In fact, last time he went to the Tug Hill area, he brought a whole case of them with him, and sold them in 10 minutes.
generally before a storm i'll put a little oil on connectors. that usually takes care of promblem, or mount plow early. be careful not to scare storm away. my father used to say i'll go put the plow and chains on and scare the snow away.
WD40 ,starting fluid,brake cleaner,all do a nice job,the starting fluid and brake cleaner melt the ice but evaporate really quick. All of these also work great in the closed environment of a truck cab when left so that the nozzle bumps in to a solid item when stopping hard provides a plowing experience thats hard to beat.
I use windsheild de icer to thaw out frozen cons. Always have it in the truck anyhow due to my other biz (towing ect. ) , works good and less extreme than a torch. Keeping them well oiled or wd40 or whatever is the best bet though. Digger, ever do a whole night in a cab with a leaky can of starting fluid? Talk about High, it's a real trip for sure! Dont keep the cans in the cab anymore is all I can tell you.
All of those methods have worked for me too. And I can't resist mentioning my spray deicer problem that I've done more than once. One particular brand comes with a scraper on the end and they put a sticker over the opening where the spray comes out. I never think to look for this so most times that it is a new can I end up spraying everything except my target because of this stupid sticker that I forget to look for. Really burns the eyes or any open wounds.
I have the same problem with mine. I brush the excess snow off, chip the majority of the ice away, if any. Then I cup the connector in my bare hands and blow into my hand for a few seconds (five or six deep breaths). The hot breath will warm them up enough to twist the collar, then no problem. It is a pain though.
I bet a rubber sleeve (that could be pulled back) to cover the connectors would work wonders!
Use a candle.Rub the wax all over the connector and get it under the sliding collar.Lubricates and keeps water out.It will last for a few plowings,and doesn't leave you hands or gloves all greasy afterwards.Sounds stupid but it works.
Most hydralic supply house carry the rubber covers that were mentioned above,but they only keep stuff out of the ends of the connector,and they will still freeze.Pick up a handful as they are cheap and do keep the connector ends clean,especially when they get left on the ground in the snow.
Sunday I encountered a frozen combo lock on the gate of an account I plow. 20F and very windy and still snowing. Tried warming with a piece of burning newspaper-no dice due to wind and snow. Tried to urinate on it-no dice due to wind and blowing snow and failure to account for "shrinkage factor" (see wind and snow comment). Finally broke down and dumped half my "Jumbo Joe" (hot coffee for those in Palm Springs) on the lock, opened right up. Maybe these ideas could help in a pinch?
Put a glob of grease on them next time and you wont have a problem. Any grease that gets in the system will dissolve and not cause a problem.
I guess I need to mention that you put the flame on the connector for about 5 seconds. You then have about 10 seconds to open it, depending on just how cold it is. You don't need to get it "cherry red"!
On frozen door locks, you heat the key for a few seconds, then open the lock. I've done that with a regular Bic lighter.