The mast's plastic string could be separated from the anchor at the spool. It should tend to feed the mast's upper section of the antenna's telescoping tube completely out of the mast base.
Double check your wiring. To raise the mast your GREEN wire is positive and your GREY wire is negative. To lower it, your WHITE wire is positive and GREEN wire is negative.
Worst case scenario -your upper and lower limiting switches are not working, but this is very un-common. The hardest part of disassembling the antenna is that the rivets that hold the housing halves together will spin on you and make it hard to drill them off without causing damage to the plastic housing. long-nosed Vise Grips will help you keep the rivets from spinning on one end while you drill off the other end.
By the way, I remember that the wires connect right at where the switches are located.