WHere can i locate the vacuum for the cruise control, I understand that this could be cracked and the reason why it is not working. THanks

 

Check the vacuum lines near the jack. This is where I found my problem, however if its not vacuum, then its the dreaded black box... FWIW get yourself the factory manual, its worth the $100 bucks

 

There are also vaccum lines hear the brake master cylinder that run to the top of the motor.... Be sure you check the fuses too I think over at Discoweb.org there was a write-up on fixing this issue....But, I have not looked there in a while...

 

you have a vac line running from the cruise vac pump, under the driver headlight, that goes to the firewall right by the master cyl. and T's off to intake area, there is a plunger looking thing there, forget the name, and from the T, it also goes into the cab to the brake pedel itself, there is a little valve body that releases vac when you press the brake.