Hi i have a 99 Expedition Eddie Buaer it has rear a/c. some times when you turn the rear air on no problems every thing works well then at times it will only blow hot air. the blower works all the time just the cooling part some times work and most of the time does not. Any help to what could be wrong would be appreciated.......thanks

 

When running the rear A/C, crawl under the vehicle and check the feed and return line where they enter the vehicle in the back. The feed line should be hot and the return line should be cold. If this is the case, then I would suspect an issue with the damper/blend assembly behind the inner A/C/ panel in the rear. If both lines are about the same temperature, you may have an issue with the expansion valve connected at the rear evaporator as they can go bad.