Fortunately, we found the initial low-speed amperage spike for this pair of 10-inch fans was only 27 amps with a continuous draw of just over 10 amps, which makes it easier on the charging system.

This pair of SPAL fans on our buddy Eric Rosendahl’s big-block El Camino consumes nearly 40 amps of continuous power. That’s a big draw if your alternator’s only capable of 70 amps.

Using a multimeter to check amp draw and line voltage helps to ensure the compressor is able to meet the expectations for the required application, said Scott Lanzer, marketing manager of digital ...