Onan MDKBT User Manual

9-3
TABLE 9-1. TROUBLESHOOTING GENSET FAULTS (CONT.)
Some genset service procedures present hazards that can result in severe personal
injury or death. Only trained and experienced service personnel with knowledge of fuels, electricity,
and machinery hazards should perform genset service. See Safety Precautions.
Accidental or remote starting can cause severe personal injury or death. Before removing a panel or
access door, disconnect the negative (−) cable from the battery to prevent the engine from starting.
WARNING
NO AC POWER WHEN GENSET IS RUNNING
(A Circuit Breaker is OFF, tripped or malfunctioning or the generator is not connected properly)
Corrective Action: Refer to Pages A-1 through A-5, as appropriate.
1. Reset, turn ON or repair the genset circuit breaker, as necessary.
2. Reset, turn ON or repair any other circuit breaker in the AC power supply system, as necessary.
3. Reconnect the generator properly for the application. See Page A-2.
HIGH ENGINE TEMPERATURE—CODE NO. 1
(Engine coolant temperature exceed design limit)
Corrective Action:
1. Check for and clean a blocked sea water strainer. If above the water line, fill the strainer with water
to assist priming.
2. Check engine coolant level and add coolant as necessary.
3. Check for kinked or leaking hoses and reconnect, reroute or replace.
4. Check the V-belt that drives the coolant pump and service as necessary (p. 4-13).
5. Inspect the siphon break for proper operation (p. 4-8).
6. Check for a worn raw water impeller and replace as necessary (p. 4-12).
7. Clean the heat exchanger (p. 4-8).
8. Check the bottom of the hull for any blockage at the through-hull fitting.
9. Replace the coolant thermostat, which might not be opening fully (p. 4-14).
10. Drain and clean the coolant system to remove coolant passage fouling (Page 4-7).
11. Test coolant sender E2 and replace if necessary (p. 5-6).
12. Disconnect connector P1 (black) from the genset controller (Page 5-1) and check for electrical conti-
nuity between Pin 9 and the ring terminal on sender E2. If it is an isolated-ground sender, also check
for electrical continuity between E2-2 and B− (ground). Repair wiring and connectors as necessary.
13. Replace the genset controller (Page 5-1).
LOW OIL PRESSURE—CODE NO. 2
(Low oil pressure)
Corrective Action: Refer to Pages A-1 through A-5, as appropriate.
1. Check the engine oil level and add or drain oil as necessary (p. 4-3). Repair any oil leaks.
2. If loose, tighten the ring terminal on oil pressure sender E1 (Page 5-6).
3. Check electrical resistance through sender E1. Replace the sender if resistance is not between
227 and 257 ohms (0 psi) when the engine is stopped.
4. Disconnect connector P1 (black) from the genset controller (Page 5-1) and check for electrical conti-
nuity between Pin 10 and the ring terminal on sender E1. If it is an isolated-ground sender, also check
for electrical continuity between E1-2 and B− (ground). Repair wiring and connectors as necessary.
5. Service the engine lubricating system. See Table 6-1 for the appropriate engine workshop manual.
6. Replace the genset controller (Page 5-1).
Redistribution or publication of this document, 
by any means, is strictly prohibited.

Onan MDKBT Specifications

General

Brand	Onan
Model	MDKBT
Category	Portable Generator
Language	English