Any ideas on what causes this? All air is blowing through the defrost regardless of what setting. Everything else is okay. AC, Heat all work fine. Just this issue of all air going through defrost.

 

you have a vacuum leak somewhere either outside or inside the truck.

 

what is the best way to look for the leak? Isnt the hose between the battery and the firewall? Interesting or just coincidence that it all started right after I replaced the battery and cleaned the corosion from the battery cables. I know just coincidence.

 

the vacuum resevoir is on the battery tray. you could have knocked the line loose causing your leak.

 

Thanks. I can see what I believe I see the line you refer to. I bet I knocked it off when putting the cover back on. Unfortunately, I don't see where it connects. any help is appreciated it. The line itself is only about 8 to 10 inches long.

 

its a black line. it starts at the resevoir and goes through the firewall. it is a thin black flexible hose

 

Thanks. I see the hose. I see where it heads into the firewall. Just need to find where it goes on the resevoir.

 

where can I get a diagram that shows me. Its obvious I have a thin hose lose. there is actually two. the one that is loose is coming off a connection that has a blue circle piece on it. Does the other end go into the connection in the white resevoir?

 

that blue circle piece is a check vavle. from there it should go to the resevoir and from there to the source for inside, but dont quote me on that not 100% sure. you should be able to get a chiltons manual for the diagram