Allison problem

I have an Allison MD 3060 in my 1994 Southwind. I finally figured out with out any doubt why my Cruise control doesn't work. It is a bad VSS (Vehicle speed sensor)signal comming from the Allison relay box (pin H2) I'm getting .3 to .8 volts AC when I vary the vehicle speed. The cruise box needs 1.4 volts AC minimum to operate. What do I need to replace?

I bought a ford transducer pickup from NAPA to substitute the VSS signal by hooking it to a power drill and verified that the Cruise control is fully functional with the substitute signal. What can be causing the poor signal from pin H2 of the Allison relay box? Please help. I can find nothing in the search.

Thanks for any help