Volkswagen Type II Transporter 1200 Series Shop Manual page 212

19--..;Electrieal Systmn
6. SP~.RK PLUGS
(1) The' sparking plugs should be removed for
. insp!)ction, cleaning. and resetting at intervals of 3000 to
4000 miles. Sparking plugs removed from an engine in good
mechanical condition, operating under normal conditions,
should have light powdery deposit ranging in colour from
light brown to· greyish tan. After considerable service the
electrodes will show signs of wear or normal burning.
(2) Sparking plugs showing a thick black oily deposit
indicates an'' engine ,'in poor mechanical condition or
possibly that
a
plug with too low a heat range has been
fitted.
(3) Sparking plugs showing a white. or yellowish
deposit indicates sustained high speed driving or possibly
that plugs of too high heat range have been fitted,
particularly when these deposits are accompanied by
blistering of theporcelain and burning of the electrodes.
Check the recommended heat range for the engine (see
specifications) and select the correct heat range if operating
conditions are abnormal.
(4) If the heat range is correct, clean the plugs on a
sanding machine, and blow clean with compressed air. Set
the electrode gap (see specifications) by bending the
earthing electrode and test the plugs on a reliable testing
machine.
NOTE: Never attempt to set the electrode gap by bending
the centre electrode, or a cracked insulator will result.
( 5) Clean the sparking plug threads and, using new
gaskets, fit the plugs, screwing up finger tight.
( 6) Using a torque wrench, tighten the sparking plugs
to the recommended torque.
7. SWIT£0 ASSEMBLIES
OIL PRESSURE SWITCH AND WARNING LIGHT
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. The oiLjJressure switch is installed in the main oil line
between . the oil pump and the oil cooler unit. When the
ignition is switched on, current flows through the warning
light and' pressure switch to earth completing the circuit
and causing the warning lamp to light.
When the engine is running the oil pressure actuates the
diaplu'agm holding. the contacts apart interrupting the
circuit and extinguishing th!) warning light. Accordingly any
failure in the oil system that results in the reduction of the
oil pressure to. a point below 8 psi is indicated by the
lighting up of the warning light.
TO TEST AND ADJUST PRESSURE SWITCH
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(1) Remove the pressure switch from the crankcase and
insta.l. a suitable T piece to enable an oil pressure. gauge to
be installed in conjunction with the pressure switch.
(2) Reconnect the pressure switch to the warning lamp
or other suitable lamp and startthe engine.
(3) Reduce the idling speed to approximately 300 rpm.
(4) Increase the engine speed to 550 rpm and note the
pressure gauge reading which should be close to 8 psi and
the warning light should go out at that pressure.
(5) If the engine has to be speeded up considerably to
obtain 8 lbs psi pressure, it is an indication of either a
faulty oil pump or worn engine bearings or other fault
allowing excessive oil to escape from the oil feed system.
Refer to · engine section specifications regards normal
operating pressure.
( 6) If the pressure reading is around 8 lbs psi at the
correct engine speed and the switch does not cut out the
warning lamp, it could require adjustment.
(7) Remove the terminal· screw from the switch. Insert
a suitable screwdriver into the slot of the adjuster screw.
Turn the screw clockwise to increase the spring loading, if
the warning light is corning on too early and anti-clockwise
to reduce the loading when the switch is operating too late .
NOTE: The sealing of the switch is effected by a tapered
thread and care must be taken not to over-tighten when
installing the unit to the crankcase
(8) The green warning light is connected to the ignition
switch and apart from replacement of the 1.2 watt bulb,
there is no maintenance involved.
8. DIRE£TION INDI£ATOR UNITS
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DIRECTION INI>ICATORS (Early Models)
The units which are recessed into the body on either
side of the vehicle just to the rear of the door pillar are
connected to' a warning light located in the speedometer
housing.
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The signal units
ar~
electro-magnetically operated and
controlled by a switch below the steering wheel. As the
units are exposed to the weather they require maintenance
in the form of removal and cleaning and lubricating from
time to time.