Generac Power Systems 5414 Test 39 - Check Wire 85 for Continuity, Test 40 - Test Choke Heater

Section 7

DIAGNOSTIC TESTS

3.Connect the test leads of a VOM across the switch terminals. The meter should read “Infinity”.

4.Heat the oil. When oil temperature reach- es approximately 270-284° F., the switch con- tacts should close and the meter should read “Continuity”.

Figure 7-46. – Testing Oil Temperature Switch

RESULTS:

1.If the Oil Temperature Switch fails Step 3 or Step 4, replace the Oil Temperature Switch.

2.If the Oil Temperature Switch is good, an overheat condition may be occurring. Verify that the installa- tion of the generator is within specified tolerances. The generator must receive the proper amount of incoming air, and also be able to exhaust the cooling air with NO RESTRICTIONS. Check to be sure that the exhaust pipe is not under the air intake. Refer to the Owner’s and Installation Manual for proper installation specifications. If installation is correct, go to Test 20.

Test 39 – Check Wire 85 for Continuity

PROCEDURE:

1.Disconnect the J1 Connector from the Printed Circuit Board.

2.Locate Pin Location J1-7 on the harness end of the J1 Connector.

3.Remove Wire 85 from the High Oil Temperature switch (HOT).

4.Set a VOM to its “Rx1” scale and zero the meter.

5.Insert one meter test lead into the end of Wire 85 disconnected from the HOT. Insert the other meter test lead into Pin Location J1-7 on the har- ness end of the J1 Connector.

RESULTS:

1.If “Continuity” is not indicated, repair or replace Wire 85.

2.If “Continuity” is indicated, replace the Printed Circuit Board.

Test 40 – Test Choke Heater

DISCUSSION:

The Choke Heater is a sensitive heating element wrapped around a temperature sensitive Bi-Metal strip. The Bi-Metal Heater Assembly positions the Choke Plate during startup. Once running, the Bi- Metal Heater Assembly will also allow the Choke Plate to fully open. Power for the heater element is supplied from Wire 14 to assist the Bi-Metal Heater Assembly in opening the Choke Plate after starting. Failure of the Choke Plate to open will cause an excessively rich fuel-air mixture and engine performance will suffer.

PROCEDURE:

1.Verify that the Choke Plate on the carburetor is mechanically free to move and is not binding. If the engine runs rough, check the operation of the Bi-Metal Heater Assembly. Allow the engine to run for five minutes, then inspect the choke position. The Bi-Metal strip should have been heated by the Choke Heater and should have expanded to allow the Choke Plate to open fully.

2.If the Choke Plate did not open in Step 1, check the Choke Heater. Set the VOM to measure DC voltage. Disconnect Connector 3 at the Choke Assembly. Connect the positive (+) meter test lead to Wire 14 (Connector 3, Pin 3) going to the control panel. Connect the negative (-) meter test lead to a clean frame ground. Set the Start-Stop Switch to “START.” Battery voltage should be measured (see Figure 7-43 on Page 63).

3.If battery voltage was not measured in Step 2, set the VOM to measure resistance. Disconnect Connector 3 at the Choke Assembly. Connect one meter test lead to Wire 14 (Connector 3, Pin

3)going to the control panel. Connect the other meter test lead to the 4-tab Connector for Wire 14 in the control panel. “Continuity” should be mea- sured.

Short to Ground:

Set the VOM to measure resistance. Connect one meter test lead to Wire 14 (Connector 3, Pin 3) going to the Bi-Metal Heater Assembly. Connect the other meter test lead to the exposed steel portion of the Bi- Metal Heater Assembly. Approximately 37 ohms (±20%) should be measured. (Current draw of the Bi-Metal Heater Assembly at nominal voltage is approximately 340 milliamps or 0.340 amps). If “Continuity” is present the Bi-Metal Heater Assembly has a short to ground.

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