I have an 2001 and all of a sudden the only place the air blows is on the defrost position on the winshield, i can turn it to the floor position, upperbody positioin, or even AC and it still blows up through the defrost vents. Has anybody ever had a problem like this before? Any input would help thanks Brett

 

Vacuum leak or Heater control module the likely culprits.

 

So you think it's either vacum or electrical i have no idea how what that switch works off of

 

Do a search on my thread entitled 97 CTD hard starting. There is a link buried in that thread that gives a 2001 service manual .PDF. It is a great big friggin file, but well worth the wait to D/L.

It should answer any questions you have and help troubleshoot your actual problem.

 

Check your vacuum lines from the pump up. The default setting when no vacuum is present is defroster only.

 

Exactly. Start under the hood. Vacuum starts at the vacuum pump, reduces down to a thin plastic vac line, and enters the cab in the same place where the heater hoses enter the firewall. Give it a good inspection, also wouldn't hurt to use a gauge to measure system vacuum. Should be over 16 inches vacuum at idle if no leaks.

 

there is a t-fitting for vacume up on your firewall if it is like mine. Check it. I bet you 4x4 doesnt work either does it?

 

Ok thanks guys i'l check out the things you mentioned

 

If its the switch control panel and you don't have heated mirrors contact me for a replacement. I have a nearly new one off my truck. Also pull the switch panel and check the vacuum plug on the back, sometimes there's white grease build-up in the holes. I used a welding tip cleaner for this, a very hand tool. Kurt