The first thing you should do for replacing the battery current sensor on a 4.3l engine is disconnect the negative
Battery Cable. Mark the battery current sensor's spot on the negative Battery Cable with tape for a quicker and easier reinstallation. Pull off the tape keeping the battery current sensor to the negative cable, then keep track of where the negative Battery Cable clips were and remove them. Hold the negative Battery Cable branches together and make sure you notice the battery current sensor's position before taking it off. Push the battery current sensor down the negative Battery Cable until it comes off. Before putting the new battery current sensor on, squeeze the negative Battery Cable together and check that it is lined up correctly. Put the new battery current sensor onto the negative Battery Cable at the spot you previously marked, and hold it on by wrapping electrical tape around its leg. Screw the negative Battery Cable clips onto the mounting holes you earlier marked and connect the negative cable to the battery.