Like i said ive got an 01 ram with 5.9 and my cruise control isnt workin, four wheel hubs arent locking and heat is stuck on defrost. I cant find a vacuum leak. Please help.

 

Follow ALL your vacuum lines. Some go down to the t-case. couple more run along the frame to the front axle. Ones goes around the front of the motor, to the cruise servo under the battery. You HAVE a vacuum leak. Just need to find it.

 

You have one or more cracked/broken vac line. They are hard to spot so you need to feel your way along each line. Start tracking off intake on passenger side until you find it.

 

May be a cracked or leaking vacuum reservoir under the wiper cowl?

 

Look on the passenger side valve cover toward the back. There's a t connection that likes to break.
There also should be a line going into the firewall toward the top of the engine bay
The 4wheel drive is run off vacuum lines, crawl up under and look. They're red, and black maybe