'87 TQ Cruise?

[Michael Spiers <mikes@specnet.com>]

On my '87 5000 TQ, I cannot set the cruise control to any speed less than 25
MPH.  This is pretty standard on any car.  Does anyone know how to access this?
 Let me rephrase that.  How does the cruise control measure the speed and then
let the system function if over a certain speed?  I'd like to tap into the
function of turning on/off a system when a certain speed is aquired, and rather
than mount another speed sensor on the driveshaft I'd like to tap into the
system already there.  I know a bunch of electronics would be involved in
setting the system up, but if I had a starting point on the cruise Ishould be
able to figure out the rest...  TIA if anyone has ideas!

-- 
-Mike
mikes@specnet.com
mks107@psuvm.psu.edu
87 5000CS TQ
84 5000S (2,000 miles away and a mile high)
90 80 (sibling's mode of transportation I get lynched into working on)