When it gets cold -- even dry and cold -- the locks on my '95 940 wagon misbehave. At 10-degrees F the tailgate wouldn't latch until I ran the heat and breathed warm(ish) air on it. The driver's door will unlock (sounds like it) but then will not open. Nothing happens when handle is squeezed -- not even a click. I've already noticed that squeezing the door handle while unlocking will confuse it, which may to be the same problem with a different cause. I've shot lube in the keyholes and latch mechanisms. Looking for direction before I go tearing off the door panels and wasting time.

Thanks.

Doesn't it get cold in Sweden?

 

I have a 740 wagon and here in Minnesota it gets cold. The rear gate gets all the road slop tossed back on it ( wagons seem to have some sort of vortex for road slop)
Their is a lock deicer sold at your favorite auto store just for this problem.
You say you slobbered it up with some lube of sorts. Not all off the shelf lubes are created equal.
Some might even compound your problem. If all else fails you might like to seek out a lock smith.
some of these guys are very reasonable and do a fine job. They understand locks and can be helpful if you can't cure this yourself.
Good luck