My son in law had something strange happen to his 98 Lariat yesterday morning. It was single digits cold here, and he went out to warm up his truck to go to work. He started it, put his key fob in his pocket, locked the truck, and went back inside. He went back out 15 minutes later, and the doors would not unlock with the fob. He thought maybe the fob battery died, so he went inside and grabbed his wife's keys, and her fob wouldn't unlock it either. He opened the door with her key and tested both fobs again - no good, wouldn't do anything. He turned the engine off and both fobs started working again. I asked him if he tried the electrical lock buttons on the doors once he was in, and he did not.

Any ideas? Is this normal? He asked all his co-workers who own Ford trucks and none of them have heard of anything like this.