2000 Winstar door ajar

I have the "door ajar" light on continuously, which causes all sorts of inconveniences. I realize this is a common problem, but after cleaning, then replacing the driver's-side switch I still have the problem.
Have traced it to the (driver's) latch itself- it doesn't snap all the way closed. With the door open I can close it all the way with a slight nudge. Have cleaned and lubed the latch. There's no adjustment slot for the latch or striker.
Do I have to replace the latch? Haven't checked yet, but I know it'll cost!

I have the "door ajar" light on continuously, which causes all sorts of inconveniences. I realize this is a common problem, but after cleaning, then replacing the driver's-side switch I still have the problem.
Have traced it to the (driver's) latch itself- it doesn't snap all the way closed. With the door open I can close it all the way with a slight nudge. Have cleaned and lubed the latch. There's no adjustment slot for the latch or striker.
Do I have to replace the latch? Haven't checked yet, but I know it'll cost!
Are you sure the problem is coming from this driver's door? A lot of problems with the door ajar light come from the tail gate latch; before planing to replace the driver latch, you could try to remove the tail gate trim and clean and lubricate the contacts. This is a regular issue for the 1999 and later Windstar model.

Yeah, I've positively traced it to the driver's door latch. It's not snapping closed all the way- when I manually close it the light goes out. Already eliminated the other doors as the culprit- this time!
Posts on this forum have been very useful for future reference and for maintenance ideas... Thanks, everybody!!!