Guardian 4702, Repair Manual

Page: 58 / 92

S Se ec cttiio on n 7 7
D DIIA AG GN NO OS ST TIIC C T TE ES ST TS S
water column as measured with a manometer. The
LP system must be able to maintain 11-14 inches
water column under all load requirements.
1. Turn LP supply to generator off.
2. Remove the Gas Pressure Tap from the fuel regulator and
install manometer to this port.
3. Turn LP supply to generator on, the gauge should read 11-14
inches water column.
4. For Problem 8 only (Section 6), start the engine and the gauge
should read 11-14 inches water column.
RESULTS:
1. If the LP gas pressure is less than 11-14 inches water column
the fuel supply system must be corrected in order to maintain
11-14 inches water column.
2. If the LP gas pressure is between 11-14 inches water Column,
proceed to Test 29 for Problem 7 (Section 6). Proceed to Test
32 for Problem 8 (Section 6).
Figure 7-29. – Fuel Regulator
TEST 29 - CHECK WIRE 14 POWER SUPPLY
DISCUSSION:
When the engine is cranked, Engine Controller Circuit
Board action must deliver battery voltage to the Wire
14 circuit, or the engine will not start. This is because
the Wire 14 circuit will operate the Fuel Pump and
Fuel Solenoid on Gasoline models. On LP models it
operates the LPG Shut-off valve.
PROCEDURE:
Inside the generator panel, locate the 4-tab terminal
connector (Figure 7-30). Then, proceed as follows:
1. Set a VOM to read battery voltage (12 VDC).
2. Connect the meter positive (+) test lead to the 4-tab terminal
connector, the common (-) test lead to frame ground.
3. Crank the engine and the meter should read battery voltage. If
battery voltage is not measured, proceed to Step 4.
4. Connect the positive (+) meter test lead to Terminal J2 on the
Engine Controller Circuit Board. Connect the negative (-) test
lead to a clean frame ground (see Figure 5-3, Page 24).
5. Crank the engine. The meter should indicate battery voltage.
Figure 7-30. – The 4-tab Connector
RESULTS:
1. If the meter indicated battery voltage, go to Test 19.
2. If battery voltage was NOT indicated in Step 3 but is indicated
in Step 5, check Wire 14 between the 4-tab connector and the
Engine Controller circuit board.
a. Repair, reconnect or replace Wire 14 as neces-
sary.
3. If battery voltage was not indicated in Step 5, replace the
Engine Controller Circuit Board.
TEST 30 - CHECK WIRE 18
DISCUSSION:
Wire 18 controls sending the STOP signal to the
Engine Controller Circuit Board. If Wire 18 contacts
ground it will initiate a shutdown. Coach manufactur-
ers sometimes install a 15 to 30 foot remote harness.
A ground on Wire 18 in a remote harness can also
cause a shutdown.
PROCEDURE:
1. Remove the remote harness connector from the generator and
re-test. If generator continues to run, a short is present in the
remote harness. Repair or replace the remote harness.
2. Remove the J1 connector from the Engine Controller Circuit
Board. Set the VOM to measure resistance. Connect one test
lead to Pin Location J1-14. Connect the other test lead to a
clean frame ground. “Infinity” should be measured.
Page 56