Buick regal OEM cruise problem

[csorb]

I have to admit I am stumped. If someone can help me solve this, that would be just great - to say the least.

Buick regal 99 cruise does not work.
tested all connections at the cruise module. The only connection that acts funny is the VSS.

The VSS sensor on this car goes into the PCM and the PCM delivers a new signal to both the cruise and the Instrument cluster. With an identical system (on a 96 Lumina) this wire climbed to 10.8 vac while on the bad cruise it never got past 4.8vac.

We have
a)changed the cars computer
b)changed the Vehicle speed sensor
c)changed the cruise module

Now the dealer who sold the car wants us to put in a brand new cruise system. I would like to repair this one. Please help. Thank you