Can't get rear gate to lock

I have used the search and found all kinds of stuff on the rear lift gate either not locking or not coming unlocked....well, that works fine on my '94.
The gate shuts securely, the glass comes down and locks, the button on the dash works...i can get in to the rear end of my rodeo with no problem...my problem is, so can anyone else...the button is always push-able and i can't for the life of me get the button to rotate (CW or CCW) from its vertical position when i insert the key...i am afraid to snap the key off as it is a bit bendable. I have tried rotating it while pushing the button in as well as leaving the button out and trying to rotate...
It will not rotate at all
I know that this has to have happened to someone out there in 15 years.
Let me know what you think....
Thanks in advance...

John

You probably need to spray some WD-40 in the lock to get the tumblers loosened up.

You probably need to spray some WD-40 in the lock to get the tumblers loosened up.
yeah, did that before i posted...didn't work yet...will do for a few more days and keep trying.
Oh, and do i need to push the button in before trying to turn the lock to the horizontal position or turn it with the button out?
Thanks

The button should not be pushed in as you try to lock it with the key. There is the possibility that the lock got replaced, with a different key and that key is now lost.

The button should not be pushed in as you try to lock it with the key. There is the possibility that the lock got replaced, with a different key and that key is now lost.

Yeah, i'd thought that too but the gate looks so nice (not butchered inside or out and the pain matches both rear quarters) that i didn't think so...would suk to not be able to lock it up...will see if wd or kroil or whatever will break it free in a few days, else i'll tear it apart...horray