Number four son's 240 wouldn’t start earlier this week. The car turned over fine. Like all good brickster's, I checked the fuses before doing anything substantial. None of the conductors were melted. I then sprayed some starting fluid into the throttle body hose. The car caught, but wouldn't keep running. Disconnecting the AMM didn't change anything. The spark plugs were dry as a bone.

I was now convinced that the problem was probable the main fuel pump. On a whim, I decided I would rotate the fuses before attempting anything more drastic. While working my down the stack, I notice that one seemed ever-so-slightly misaligned. It just happened to be the fuel pump fuse. I pulled it, and noticed that while the conductor was perfect, the plastic fuse body was slightly melted. The plastic ran down via capillary action between the conductor and holder terminals. Apparently, the fuse was forced very slightly out of the holder during an earlier anti-corrosion rotation. The reduced contact area increased the electrical resistance, which generated enough heat to resistance was enough to soften the plastic body.

The moral of the story is to look at more than the fuse conductor when checking fuses. If a fuse seems slightly misaligned, even if it rotates and as a perfect conductor, pull, inspect, and clean it before moving on to a more time-consuming diagnostic step.