First may want to check that the cable returned. Sometimes it will seize up in its housing. Underneath the truck, about where the cab ends and the bed begins - should see a cable splitter - grab hold of each side of the rear cables and pull back (rearward) hard.
You may try to back up to see if that will free things up. If these actions don't get it - may try dialing the star adjuster wheel in as far as it will go. If that doesn't get it, hmm - may just have to cut the cable at the rear drum - but do this only as a last resort.
1989 F150 XLT standard-cab shortbed 4x4, 5.0L, AOD, 3.55 gears, manual hubs, 31x10.50 tires, 218K miles. Repainted Oct09. SOLD - Jan2015
2014 F150 XLT standard-cab shortbed 4x4, 5.0L, 6-speed auto, 3.55 gears, auto hubs, locking diff, trailer pkg, 5K miles.