A combustion reaction takes place inside the catalytic converter, an exothermic reaction that raises the heat level of the exhaust system by several hundred degrees. The internal temperature of the converter can rise as high as 1600 degrees fahrenheit. The temperature of the shell can skyrocket to 2500 degrees fahrenheit or more. Electrical fires in the modern automobile are uncommon, but they can occur. The electrical system uses a number of safeguards to protect against overloading and thus potential fire causes. Today there are not only gasoline powered vehicles but a number of propane powered vehicles. The fuel system itself is relatively the same as the gasoline engine. When an investigator is examining a vehicle fire, it is important to avoid preconceived ideas about what happened. An examination of the electrical system should start with the wiring in the area of fire origin. A check of the battery may tell if it is still energized or if it has been totally de-energized. A totally or partially energized battery usually indicates that one of the safety links worked and stopped the flow of electricity. Because of its high temperatures, the catalytic converter is an easy source for blame. There is shielding to prevent its heat from getting to combustible material. A check of this will determine if the shielding is still in place and whether or not it was damaged. Finally, the fuel system should be checked from tank to engine. Two tables, three footnotes, and a seven-item bibliography are included.