Intermittent Door Locks

I have a 2000 F 250 Super Duty (7.3 Turbo Diesel) with 99,600 miles, automatic transmisison, power windows, and locks.
The Problem is that I had an alarm system put in this past winter, and when the weather is Cold, the locks Worked fine. But when it started warming up they quit working. They will work VERY occasionaly. I took it back to the car alarm place and he thinks its the Body control module. I had a Python alarm system installed.

I checked the Fuse and it was a little bit corroded so I changed that still same problem.

Any Ideas

Blue in Fort Worth (wheres its HOT most of the year)