Tailgate lock not locking

[RamRod1]

I recently bought a 2012 quadcab and just noticed that the tailgate does not lock. The key turns but doesn't lock it.
There's a spray in bedliner so if I have to unscrew the panel, I don't want to damage it. I should also mention that the truck came with 2 key fobs (with the real key inside) and no other key.
Any help would be greatly appreciated

 

[mrack]

Can’t give you any ideas, but don’t be scared to pull that panel off, bedliner is made to be beat on, your not going to damage anything

 

[RamRod1]

Here's an update: I opened it up and sprayed WD-40 all over it as well as in the key cylinder. after a bit of wiggling and jiggling everything seems to be working again. Seems to have been jammed from lack of use. Should I put oil on it or just leave the WD-40?

 

[chopperman1]

You should use a dry lube, not an oil based one.

 

[Dean2]

Silicone Lube or dry graphite works good on locks. WD40 is a great water displacer, rust remover and bolt removal assistant but a truly lousy longer term Lube. It attracts dirt when new and leaves a sticky, varnish like residual once dried out.

 

[RamRod1]

The cylinder worked, it was the mechanism that was stuck from lack of use. The WD-40 worked and the mechanism now works smoothly. I wiped up as much of the WD-40 as I could see and I'm going to spray the mechanism with silicone because there's plastic and metal parts. For the cylinder I'll use a little graphite. Thank you all for your help