I'm sure its too late now, but did it come down just a little bit and stop? If it did, it was hanging up on the "safety" latch. Not sure what years/models had this but my 2006 did. I never got it to work using the instructions from the manual of pushing up with the jack to release the safety catch. I had to lower it the few inches it would go down, and then finagle the tire out of the way using the jack on one side to tilt it out of way just enough and then I believe I went in through the hole behind the license plate and grabbed hold of the latch with a pair of channel locks and squeezed the latch so it would unhook. It dropped loose after that. Pretty sure I "deleted" the safety catch afterwards, either by zip tying it so it couldn't spring out and latch anymore or grinding the catch off. I don't remember which and I've since sold the truck so I can't go look. Hope that helps somebody.