Smiths Aerospace
Electronic Systems – Malvern
DOC NO.0134ED
MAINTENANCE MANUAL SUPPLEMENT
BOEING B737-100/200/300/400/500
28-41-04
(5) Open these circuit breakers and attach DO-NOT-CLOSE tags:
(a) P6 Main Power Distribution Panel
1) FUEL
QTY
2) EP GND FUELING
CAUTION:
POWER MUST BE REMOVED FROM FUEL QUANTITY INDICATORS
WHEN CONNECTOR IS REMOVED OR DAMAGE TO INDICATORS MAY
RESULT.
(6) Remove the fuel quantity indicator and the DCTU from the pilots’ panel (Fig. 501),
(AMM 28-41-04/401).
(7) First, disconnect the indicator from the DCTU, next, disconnect the electrical connector from the
rear of the DCTU.
(8) Do this task: Fuel summation Unit removal or V-Ref/Totalizer removal as applicable (AMM 28-41-
81/401).
(9) Connect the test equipment.
(a) Connect the test harness to the airplane wire bundle.
(b) Connect the test harness to the test unit
(10) Do this task: Fueling indicator removal (AMM 28-41-04/401).
(11) Disconnect the TSU J1 and J2 connector plugs and install TSU jumper harness 201475-001 to
airplane wire bundle and tank harness. Connect harness ground jumpers together, and do not
ground to airframe.
E. Test
Procedure
(1) Measure the empty tank resistances (Fig. 502).
(a) Set the power switch on the test unit to ON.
(b) Set the FREQUENCY SELECT switch (PSD60-2R) to 7,400 Hz and press to set.
(c) Set the FUNCTION SEL switch to MEG (not SELF TEST MEG) (PSD40-1) or set the FUNCT
switch (PSD60-1, -2) or FUNCTION SELECT switch (PSD60-2R) to MEASURE EXT.
(d) Set the FUNCTION MEASURE switch (PSD40-1) or set the SELECT switch (PSD60-1, -2) or
MEGGER SELECT switch (PSD60-2R) to LOZ-HIZ.
(e) Read the total resistance for the tank units.
(f) Make sure the resistance shown on the test unit is more than 250 megohms.
(g) Set the FUNCTION MEASURE switch (PSD40-1) or set the SELECT switch (PSD60-1, -2) or
MEGGER SELECT switch (PSD60-2R) to COMP-HIZ.
(h) Read the total resistance for the compensator.
(i) Make sure the resistance shown on the test unit is more than 2000 megohms.
CONFIG
4.2
Page 505
April 19/02
Airplanes with Smiths 2307 Model Fuel Quantity Indicators
with TSU
(SIMMONDS SYSTEM TESTER)
EFFECTIVITY