ok, i figured out that the 4x4 and vents run off of vaccum. where does the truck make it's vaccum. i'm used to gassers and manual hubs so this has never been an issue before. also where would the fuse/relay be to control it.

on a side note i killed third gear the same day this other junk went out. third gear was worth it since i got a 6.0 power smoke redlight to redlight with his little Banks badges all over it. so i guess it's time to put a 6-speed in the truck.

 

ther is a vacuum pump attached to your power steering pump

 

is there anything electronic going to or from that pump setup or a central vacum block where the lines branch off to different acc.

 

couldnt tell you on that, but I have seen where brake fluid has dripped onto the vac hose for the axle disconect and deteriorated the hose resulting in no 4x4------someone more familiear with your truck will chime in soon

 

Right in the middle of your firewall (maybe to the right of the head a tad) is a vacumme T. Check to make sure it hasn't come unhooked. If it is still connected tracing everything from this point is a breeze. I had this same exact problem just a few weeks ago and found that that line was disconnected down below.

 

thanks for the help, tomarrow when i get home i'll check it out. i had no clue as to how diesel's make vacum. hopefully it's just a dag'on loose hose

 

It's also pretty common for battery acid to cause the vacuum line to the cruise control servo under the driver's side battery to fail and for the vacuum line that runs along the top of the firewall and then into the cab for the HVAC system to come lose, drop onto the exhaust, melt, and fail.

 

Easy way to tell if you have a vacuum leak is to disconnect a vacuum line after the truck sits for a few hours. If you don't hear a hiss you have a leak. Most rigs will hold a vacuum and hiss when disconnected even after sitting for several days.