there would also be a diffrence between automatic and standard transmission trucks. last I checked on the stick shifts the cruse was controlled through the ecm alone, no vaccume.....

 

Interesting Info! I wonder why they mixed the use of the vacuum? I know the manual is more complicated to deactivate. On the auto it get its input to deactivate from the brake circut. On the manual if you push in on the clutch pedal it needs to know that!!
Hauliday I like that unit! I bet it works better than elec brakes! If I already had a hyd. on my trailer it would be the way to go! If I have more problems with them I will!