Gleaner L3

We just bought a 1983 L3 we went to cut beans and have no header hight control. Anybody know how to fix this.

IF the basic check Doc posted doesn't work - do these checks - with a test light you should have current on the 3 springs on the RH side of the head on the big plastic rotary switch the middle is mid - others are low/high - (this does not make the header cut higher or lower) Then the brass bar will touch the springs and send back current thru the blue wire to raise or the red wire to lower. Check at the switch and the plug in for the header - at the plug in there is a jumper on the red lower wires and BOTH red wires have to have feed back current to make it lower. Many times the wires will break INSIDE the harness where the throat pivots and you get input current to the control module at the switch but it never makes it back to the module.
The module has to have power from two sources The orange wire then the red/yellow wire to the module.   The HIGH MED LOW switch also had to receive power /volage as well from the orange out power wire to the switch.    The early modules were not sealed - few still exist and they had only one power wire.