I just finished putting in some 6x9's in my cargo area, and having to take off the cargo side panels and the seatbelts to completely get them off, I managed to let the seatbelt wind up to the point that the tensioner locked. What can I do to unlock 'em!?

 

did you remove them when you put the speakers in?
I did this when I pulled a set at the junkyard. pull them again and try wiggling them around. that is how I got mine to release, they had to be at just the right angle...

 

They are not locked up. The belts only work at a certain angle, so hold them like they would be mounted in the truck, and they will work just fine.

 

Yep, I had to let them retract to get the panels off. Do you remember at which angle exactly? I've been trying, but no luck.