WATER TEMP, OIL PRESS, OR FUEL GAGE INOPERATIVE (Cont)

TM 9-2320-285-24-1

2-83.

PRESSURE GAGES TROUBLESHOOTING (CONT)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

WATER TEMP, OIL PRESS, OR FUEL GAGE INOPERATIVE (Cont)

Step 2.

Remove gage electrical lead at sending unit; have assistant momen-

tarily ground electrical lead to engine block or frame of tractor.

Start engine; watch gage pointer.

If gage pointer deflects to approximately full scale, sending

unit is defective; replace (para 2-32a, 2-32c, or 2-32d).

If gage pointer does not deflect, go to step 3 below.

Step 3.

Check gage for loose or incorrect connections and broken conductor.

If connections are loose or incorrect, tighten or correct (para

2-87a, 2-87c, or 2-87d).

If conductor is broken, replace (para 2-87a, 2-87c, or 2-87d).

AIR PRESS GAGE DOESN'T INDICATE CORRECT AIR PRESSURE

Step 1.

Raise instrument panel (para 2-26g(1)).

Check AIR PRESS gage hose for restrictions (sharp bends, blockage).

WARNING

Compressed air must not exceed 30 psi. Wear safety glasses when using compressed

air. Failure to do so could cause serious injury to eyes and possible blindness. If you hurt

your eyes or if a foreign object is blown into your eyes, seek medical aid immediately.

If hose is blocked, use compressed air (30 psi maximum) to

remove blockage; if hose remains blocked, replace (para 2-87b).

If hose is not blocked, go to step 2 below.

Step 2.

Open drain cock on service air tank to relieve air system pressure.

Disconnect electrical leads from terminals of low air pressure

switch, and remove switch (para 2-51c).

Install a calibrated air pressure gage in tee from which low air

pressure switch was removed.

Close drain cock on service air tank.

Start engine and allow air system to charge to 50-100 psi.

Compare indication on AIR PRESS gage with indication on test gage.

If AIR PRESS gage indication differs from test gage indication by

more than 10 psi, replace AIR PRESS gage (para 2-87b).

2-909