My rear a/c and heater, blower doesn't work why. Front work fine.. .. ...
Sunday, December 22nd, 2013 AT 1:04 PM
Can you please hold your computer closer to the vehicle so I can diagnose it?
The reason for the 200 character minimum is to force you to provide at least a tiny hint of details or observations so we don't have to guess. Would you call your doctor and tell him you're in pain; why? It could be a stomach ache, a hang nail, or you cut your foot off with a chain saw. You don't really expect us to know what's wrong with the fan, do you? This is where you need to get a live person involved who can actually listen to it and look for the clues you didn't provide.
This may be hard to believe, but mechanics aren't psychic. If you can't tell him any observations, he is going to require more time for the diagnosis, and that translates into dollars. That is not his fault. Some things you might be able to share include, 1) did it quit suddenly and never work after that? 2) Did it stop working a while ago, then it worked for brief periods a day or two later? 3) Did all the speeds quit at the same time? 4) Do you have mechanical switches for the heater or are they touch buttons? Buttons are used with a computer, and this environment is hard on computers.
If it worked intermittently, we know it's not a fuse issue, because fuses don't fix themselves. Now we know it's not a shorted motor or grounded wire to it.
If only one or two speeds quit at first, the motor was still working and the circuit supplying power had to be okay. That just cut the list of possibilities in half, and that saves you time and money.
You didn't even say if you checked for a blown fuse. If you can't do that, it's doubtful I can lead you through numerous pages of a diagnostic manual. If you know how to read a wiring schematic, Ford has really nice books called "EVTM" manuals. That's "Electrical and Vacuum Troubleshooting Manual". You can find them for less than ten bucks on eBay. They put the entire circuit on one or two pages, and every component is shown, and there's a lot of notes that tell you what to check for and what you should find.