The first point is to know that there are two different types of internal wiring harnesses among Dodge, Mitsubishi and Nissan vehicles. Mitsubishi and Nissan provide an internal ground for all their solenoids and the stepper motor (Figure 1); Dodge provides an external ground for three solenoids (Figure 2).
The last thing I want to do is put you to sleep with an article on performing electrical tests and Ohm’s Law. What I want to show here is something that I think is really exciting: load-testing solenoid circuits with an ammeter! Using an ammeter and a calculator can save time, LOTS OF TIME. How would you like to check the power distribution, ignition switch, external and internal wiring, solenoids, computer and computer grounds without putting the vehicle on a lift or even raising the hood?