My 2003 Lariat will not switch from defrost to floor. there are 5 vacuum lines to heater control. between the red & blue hose there is an empty connector. Is it missing a vacuum line? Can't find one laying in behind. Any other thoughts?

 

Check for any blockage in the system??

 

there are 3-4 vacuum cylinders that stroke different doors to direct the air to defrost, vent, floor, and outisde fresh air. If you have no vacuum, the doors all close and the air goes out the defrost. You definitly have a loss of vacuum. i dont know about that hose or fitting, but normall place to loose vacuum is on teh outside of teh firewall, between motor and glovebox area. Ssmall black hose can crack, the plastic TEE can crack,or the accumulator tank can crack or leak. The vacuum accumulator is inside the passenger fender well, behind battery. You need to check the hose there, and at fire wall and see if there is vacuum.

 

Thank You. Will check today.

 

MAYBE THIS WILL HELP OUT EVERYONE LOOKING FOR INFO

 

try the below link



I changed the 4 o rings inside the EATC or head unit. $2 for parts.

I followed these instructions!!!!

Repaired my EATC module today. - MercuryMarauder.net Forums



thanks JACook