Table 4-2. Unit Troubleshooting Guide (Continued)
TEST OR INSPECTION
Step 4. Check inlet of pump for plugging.
(a) Remove anything that is plugging pump.
(b) Replace distribution pump/motor assembly (para. 4-87).
1. Diesel heater smokes heavily when operating.
Adjust carburetor (para. 4-60).
2. Diesel heater shuts down at room temperature instead of going to standby.
Inspect thermostat assembly (hold-fire).
Adjust thermostat assembly (para. 4-60).
1. Cover gasket leaks.
(a) Replace gasket, if damaged (para. 4-65).
(b) Repair clamps if necessary (para. 4-65).
2. NBC filter assembly leaks.
Inspect valves or fittings for leak.
(a) Replace valve/repair fittings (para. 4-65).
(b) If the filter vessel leaks, notify direct support maintenance.
3. NBC media in product tank.
Notify direct support maintenance.
All schematics and interconnection diagrams are located in Appendix I.
Malfunction 1 is a list of General Procedures for electrical troubleshooting.
1. Electrical problems.
Step 1. Follow these general procedures. Electrical problem troubleshooting can be very simple if a few basic
rules are observed.
In order to do work, electricity must go somewhere; from hot to neutral. The ROWPU electrical
schematics are set up with the hot line on the left and the neutral on the right side of the ladder
Electricity must go through a load device such as a coil, a motor, a light, or a resistance of some
sort before going to neutral. It cannot go through a switch device, such as a relay contact, and then
straight to neutral as a dead short will result.
The horizontal lines between the vertical hot and neutral lines are the paths the electricity flows
through to do work. If it encounters an open contact, a switch or a loose wire, it stops and nothing
more will happen to the right of the open circuit.