TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
Page 396 of 890
TM 9-2320-280-20-1 2-31. GLOWPLUGS CIRCUIT TESTS (PROTECTIVE CONTROL BOX) These tests of the Glowplugs Circuit can be run anytime you think there may be a problem with the glowplugs, or if you were sent here from another test. If you were sent from another test, be sure to mark where you came from so you will be able to return. If you are running this test because the engine is hard to start when cold, remember that there is also a cold start advance circuit (part of the fuel system) which is not checked here. For any starting problem, we recommend running the “STARTABILITY” test chain just to be sure you don't miss anything. At the bottom of this page is a simplified block diagram which shows how the different parts of the glowplug circuit depend on each other and on other engine circuits. Refer to fold-out page FO-9 and leave it open for reference while preforming these tests. The fold-out diagram is arranged to allow you to follow the diagnostic logic and understand what you are testing, when and why. ALTERNATOR A.C. LEAD INSTRUMENT POWER GLOWPLUG CONTROLLER PROTECTIVE CONTROL BOX WAIT-TO-START LAMP GROUND GLOWPLUGS CIRCUIT SIMPLIFIED BLOCK DIAGRAM FOR PROTECTIVE CONTROL BOX BATTERY ALTERNATOR Change 1 2-303 GLOWPLUGS