Generac Power Systems 8 kW LP, 10 kW LP, 13 kW NG manual Test 76 Check High Oil Temperature Switch

Section 4.4

Diagnostic tests

Part 4

DC control

a. Disconnect the J1 Connector from the printed circuit board.

b.Connect one test lead to Wire 86 (disconnected from LOP). Connect the other test lead to Pin Location 4 (Wire 86) of the J1 Connector at the Circuit Board (for all models). CONTINUITY should be measured. If CONTINUITY is not measured, repair or replace Wire 86 between the LOP switch and the J1 Connector.

c.Connect one test lead to Wire 0 ( disconnected from LOP). Connect the other test lead to a clean frame ground. CONTINUITY should be measured. If CONTINUITY is NOT measured repair or replace Wire 0 between the LOP and the ground terminal connection on the engine mount.

7.If the LOP switch tests good in Step 5 and oil pressure is good in Step 4 but the unit still shuts down with a LOP fault, check Wire 86 for a short to ground. Set a VOM to measure resistance. Disconnect the J1 Connector from the circuit board. Remove Wire 86 from the LOP switch. Connect one test lead to Wire 86. Connect the other test lead to a clean frame ground. INFINITY should be measured. If CONTINUITY is measured, repair or replace Wire 86 between the LOP switch and the J1 Connector.

RESULTS:

1. Replace switch if it fails the test.

Test 76 – Check High Oil Temperature

Switch

DISCUSSION:

If the temperature switch contacts have failed in a closed position, the engine will fault out on “OVERTEMP”. If the unit is in an overheated condition, the switch contacts will close at 293° F. This will normally occur from inadequate airflow through the generator.

PROCEDURE:

1.Verify that the engine has cooled down (engine block is cool to the touch). This will allow the contacts in the High Oil Temperature Switch to close.

2.Check the installation and area surrounding the generator. There should be at least three feet of clear area around the entire unit. Make sure that there are no obstructions preventing incoming and outgoing air.

3.Disconnect Wire 85 and Wire 0 from the High Oil Temperature Switch.

4.Set a VOM to measure resistance. Connect the test leads across the switch terminals. The meter should read INFINITY.

5.If the switch tested good in Step 4, and a true overtem- perature condition has not occurred, check Wire 85 for a

short to ground. Remove J1 Connector from the circuit board. Set the VOM to measure resistance. Connect one test lead to Wire 85 (disconnected from High Oil Temperature Switch). Connect the other test lead to a clean frame ground. INFINITY should be measured.

Testing High Oil Temperature Switch:

6.Remove the High Oil Temperature Switch.

7.Immerse the sensing tip of the switch in oil as shown in Figure 43, along with a suitable thermometer.

8.Set a VOM to measure resistance. Then, connect the VOM test leads across the switch terminal and the switch body. The meter should read INFINITY.

9.Heat the oil in the container. When the thermometer reads approximately 283°-305° F. (139°-151° C.), the VOM should indicate CONTINUITY.

Figure 43. Testing the Oil Temperature Switch

RESULTS:

1.If the switch fails Step 4, or Steps 8-9, replace the switch.

2.If INFINITY was not measured in Step 5, repair or replace Wire 85 between the Circuit Board and the High Oil Temperature Switch.

Test 77 – Check and Adjust Valves

Discussion:

Improperly adjusted valves can cause various engine related problems including, but not limited to, hard starting, rough running and lack of power. The valve adjustment procedure for both the single cylinder and the V-twin engines is the same.

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