Go to your truck, pick up a contactor, and look at it closely. You may find some interesting ratings you never noticed—things like terminal ambient temperature ratings and torque specs. One reading you may overlook is the RES AMPACITY of the contactor or relay. The RES rating is the RESISTIVE LOAD AMPACITY (amperage capacity) or rating. […]

Ohm’s law is pretty straightforward; you multiply ohms by amps to get the voltage. Using variable E to represent voltage, variable I for amps, and variable R for ohms, the equation for Ohm’s law looks like this:  E = I × R  You can figure out the number of amps in a system using basic […]

  One of the most common mistakes I hear techs make is confusing zero ohms with infinite ohms. The fuse above is showing near-zero ohms, which indicates a good electrical path with very little resistance. If there is a perfect path, it would have zero ohms (which isn't actually possible unless you happen to be […]