The key action alone will not lock or unlock doors. I have to finish it myself by hand by pushing down or pulling up on the rod. I had the panel off and inspected the piston and all the mechanisms. The piston is just not traveling quite far enough on it's own to lock or unlock. This just happened after our first rain last week. Any suggestions on action to take? I sprayed some WD 40 in there but no help. Thanks

 

It HAS to be a matter of something sticking-I'd lube all the linkages and make sure they move freely and don't bind. Volvos get like that in the doors-with the years they dry up or rust and, well, you know... Also, good idea to lube up the pivot points and surfaces of the window regulator while you have the panel off...

 

I think Tedv is right, you probably have sticky (hopefully not rusted) lock mechanisms. I recently had my 1993 240 wagon painted, and removed door panels, door handles, locks, etc. The locks on the driver's and passenger's doors were dry and a little oxidized. I sprayed them with lubricant and let it soak in, and lubed every spot I could find that might need it. When I put everything back together the locks worked like new.

If you are getting water in the doors, check your window scraper moldings and see if they're too worn. IPD sells a complete kit for four doors for $90.