You have to remove the control valve. The lowering spool activates a 5 volt(?) switch, which activates a 12 volt soliniod, which in turn allows for oil pressure to release spring pressure lowering the load.
If you remove the soliniod, you'll come to the 1st spring and poppet, then you'll see a hollow cigar shaped holed cylinder regulator valve. Remove that and you'll see a broken spring, thats the problem.
P/N is 67609-26601-71, 67609-26600-71 (5000lbs). There are 2 #'s listed on the parts sheet and only the second # is listed on the bulletin. I dont know if they are the same part. E-mail address?
What p/n did you order and where did you get it?