I have a 2004 Excursion 6.0 with an A/C controller issue. On hotter days, the AC controller on the dash will not turn on. Sometimes I can cycle the truck and it will work, other times it will not come back for the rest of the day, and other times it will be as long as three days before the controller turns on again. It has been happening since new and I have taken it to the dealer to show them multiple times but it always "fixes" itself before anyone looks at it. Service managers have seen the issue but no luck with them either. I have learned to live with it in the 300,000 miles on the truck. It happens when its hotter and never when I need the heat setting.

So yesterday, I get in the 2002 Excursion 7.3 with 90,000 miles and the same happens. I don't think much of it as I don't realize the truck i'm in and drive off. about 15 minutes later, it comes on and life is normal again. It was 85 degrees out but the truck came out of a garage.

Since this is now happening in both trucks, I can not imagine I'm the only one that has this issue. Has anyone else out there experienced the same? Any suggestions on how to fix it? Black trucks in the summer are quite hot and I'd love to remedy this!

 

You have to get factory service manuals and find where the power comes from. There are some really good trouble shooting sections.

 

Thanks Lance!

I guess after reading my post that I may not have quite clear, it is quite difficult to troubleshoot as it always corrects itself. The dealer has had it probably no less than 30 times in the 17 years that I've had the 2004 truck, with no luck on fixing it as it always fixes itself before they can troubleshoot it. I have the same issue as when I believe I have "fixed it", the issue comes back again. Unplugging, plugging, testing voltage, etc. always seems to yield the same results, that it is magically fixed until it happens again.

Has anyone seen a defect possibly internally in the control units? As the Ford guys can swap these out easily (because they have them on the shelf), it is much more difficult for me to get the expensive parts to troubleshoot. Any other ideas?

Thanks all!

 

Next time it happens, cycle the headlights on and off a couple of times and it should come back on. There's a relay in the system somewhere (have never figured out where) that needs to be power cycled for it to come back on. It's a well known issue but I've not seen anyone actually find a fix for it.

 

Thank you - that's the kind of info I need to stop driving me crazy. I will try that!

I'll update the thread when it happens again with the results. Of course now it won't happen again for a while.. :-)

 

Some diagrams for you.

 

I have a similar, probably related, problem. My A/C is always engaged. I can get heat, but the A/C compressor is always running. I was thinking it might be in the switch. That would be too easy.

 

Are these automatic (EATC) or manual climate controls systems? Note: The diagrams in post #6 are for the manual system.

 

Probably not the same. Suggest starting your own separate thread.