When diagnosing a low battery or no charging system concern, start by inspecting the SA1 200 amp fuse in the SA fuse block. DO NOT replace the generator. Perform a voltage drop test between threaded connections 508 and SA1 as shown in Figure 1. If the voltage drop is above .02V, disconnect the battery and remove the cables at the 508 connection and the SA1 connection. Check for continuity of the threaded plate connection between 508 and SA1. If fuse SA1 is found to have an open circuit, replace the fuse and check the threaded connections closely.