I have a simular issue. If my 2008 Lariat SuperCrew sits in the sun and gets hot it will not start. I have to open the windows and hood to let it cool off. After about 15 minutes my truck will start with no further issues. This only happens about twice a week. The computer isn't throwing any codes. I installed a viper alarm/autostart system in Feburary. My problems didn't start until about March. I have been told that the factory door locking system may be counter reacting the alarm system. I will get under my truck today and check the starter wires. I have tried to locate the solenoid on the fender with no luck. Is there one on the 2008 models or is it mounted to the starter? Any help will be great.

P.S.
I have looked for other threads but this is the only one that's close, unless I missed one.

 

I only have the problem when my truck sits in the sun for an extended pierod of time. What parts could tempature have an affect on? I just assume the altenator would be consistant and not just with the weather. I hope to find the solution soon.

 

I also wonder if a Ford dealership would know anything about this as it seems to be a normal problem.

 

Moved to correct section