A diagnosis of any electrical system, whether it is 12 or 24 volts, must include two key elements. First, you must test the complete circuit. Second, you must understand how that circuit works. One of ...

We'll explain how to use an OBDII code reader to clear Cummins fault codes, and we'll also explain how to clear the codes if you don't have access to a scan tool.

Sure, you could spend the money on a good Ford-specific EEC-IV diagnostic code reader, but why do that when you could just as easily test for trouble codes manually? Yes, you heard that right.