keyless entry

I have a 95 Chevy lumina apv and I have tried to program the keyless entry for it I can get the doors to unlock but not lock and I have to press the button on the fob a million times if you have any advice I would really appriciate it .

Its possible that one of your switches is stuck or sticking.

I have two remotes and they both do the same thing. I took the van to the dealership and they couldn't get it working right, but I later discovered that the reciever was bad i replaced it and now this is what's happening.