ARMY TM 9-6115-670-14&P 6-88 6.35.  MAIN RECTIFIER ASSEMBLY. This task covers:     a.  Inspect b.  Test c.  Repair INITIAL SETUP Tools Shop Equipment, Electrical Repair, Semitrailer Mounted (Item 3, Appendix B) Equipment Conditions Exciter stator removed (para 6.34.). Materials/Parts Main Rectifier Assembly Diodes Varistor INSPECT Inspect varistor (1, Figure 6-32) and replace (REPAIR, steps e - f) if showing signs of deterioration. TEST a.  Tag and unsolder leads (3) from diodes (2). b.  Loosen nut (4) and remove diodes (2) from rectifier assembly (5). c.  Use diode checker on an ohmmeter to test diodes. Replace bad diodes (REPAIR, steps a - d). REPAIR a.  Tag and unsolder leads (3) from diodes (2). b.  Loosen nut (4) and diodes (2) from rectifier assembly. c.  Install diode (2) and secure with nut (4). d.  Solder lead (3) to diode (2).  Remove tag. e.  Remove two bolts, lock washers (6), and remove varistor (1). f.   Install varistor and secure with two bolts and lock washers (6). CAUTION When replacing, observe the polarity of the diodes.  Place positive diodes in positive position and negative diodes in negative position. WARNING Ensure    that    the    APU    is    off    and    completely deenergized before working on generator.  Failure to heed  this  warning  could  result  in  severe  injury  or DEATH by electrocution.