AC control switch or vacuum leak?

Scrapiron

New Member
Joined
Dec 6, 2020
Messages
4
Location
Tucson
I have a 2006 LJ that has just developed the common problem of lack of air flow control. All control positions result in air flowing through heater/defrost vents. I have looked for vacuum leaks and find none. The cruise control works. My guess is that the problem is in the switch. The blower control is fine, but the blower switch is fully operational with the system “off”. The ac/heater switch does not have solid clicks when switching functions. Could the function switch be the problem?
 
While there is a very good chance that the problem is the mode selector control switch; the problem may also be the damper actuator or the incoming vacuum to the climate controls. You will need to verify you have vacuum to the mode selector before you can rule out the mode selector or the damper actuator. IF you have vacuum coming into the mode selector then test for vacuum going to the damper. Then you will need to test the actuator with an separate vacuum source to see if the actuator functions.
 
Last edited:
While there is a very good chance that the problem is the mode selector control switch; the problem may also be the damper actuator or the incoming vacuum to the climate controls. You will need to verify you have vacuum to the mode selector before you can rule out the mode selector or the damper actuator. IF you have vacuum coming into the mode selector then test vacuum going to the damper. Then you will need to test the actuator with an separate vacuum source to see if the actuator functions.
Thanks for the information. I have not checked the lines to the damper. I’ll get back on it today.
 
Mine was as simple as a vacuum line that came off the engine near the cruise control servo... I had also lost cruise. If you have cruise and it still works, that would narrow it down to the switch.
 
Thanks for the response. I think you may be right about the switch. I will go over the vacuum lines again, but I will order a new switch anyway. It does not feel right.
 
Mine was as simple as a vacuum line that came off the engine near the cruise control servo... I had also lost cruise. If you have cruise and it still works, that would narrow it down to the switch.
I just ordered a new control panel. Thanks for your input.