Schumacher PST-1000 - Manual (Page 3)

3
EXTERNAL VOLTS LEADS (1 mg ohms)
These leads may be used for measuring any DC voltage on a
vehicle when the test selector switch is placed in External posi-
tion. The voltmeter circuit is isolated and has an automatic polar-
ity indication. Typical applications are for measuring load volt-
ages and cable connection voltage drops.
AMPS DISPLAY
The display shows the amperage sensed by the Amp Probe. The
readout is in 1 amp steps and has a working range up to ±1999
Amps.
AMP PROBE LEAD AND ZERO KNOB
The inductive Amp Probe senses current in a wire without having
to disturb any connections. Place the wire through the opening
and check that the probe jaws close fully. The + - sign on the
probe indicates the direction of conventional currents, which will
give a positive display reading. Reversed currents will show a
minus sign. For example, if the probe is on a negative ground
alternator output wire with the + sign towards the alternator, the
reading will be positive. Switch to 1000A position and use the
zero auto adjust knob (on probe top) to cancel offset before probe
hookup.
Note: The probe works by sensing magnetism around a wire. To
avoid errors keep it away from the back of the alternator and
other strong magnets. Probe uses a 9 volt battery inside of the
back.
DIODE/STATOR LAMP
This lamp will be on steady when there is alternator output of at
least 20 amps and excessive “ripple” is detected in the battery
cable. Ignore momentary flashes. Alternator output with ripple
current are usually caused by a bad diode or stator winding.
LOAD CONTROL KNOB
This load is suitable for 6 to 24 volt automotive battery systems.
The Load control knob is used to adjust the battery test current.
The load is a carbon pile capable of drawing 1000 Amps. Draws
of over 100 amps must be limited to 15 seconds with a minimum
of 60 seconds off between tests to avoid heat buildup. The fan
will come on when the test load reaches 50 amps and will remain
on until the temperature drops below 60°C. If the fan air feels
warm, allow it to run after testing to reduce the damaging effects
of high temperatures.
AVOID DANGEROUS SPARKS
Always turn the Load Knob “OFF” before connecting or mov-
ing the battery clamps.
LOAD-ON LAMP
When the lamp is lighted, the carbon pile is drawing at last 50
amps from the battery and it is a reminder to turn off the load
when the test is complete or before changing battery connec-
tions.
Note: The Load-On lamp will not be bright enough to see during
6V battery tests.
TIMER BEEPER AND TIME OUT LAMP
When the Load-On lamp begins lighting, an internal timer waits
15 seconds and then begins sounding an audible beep and the
“Time-Out” lamp illuminates. Both are reminders to turn off the
load before removing or moving the battery cable clamps from
the battery.
ANALYZER HOOK UP
All of the test procedures of a vehicle’s equipment presume that
the battery will perform well enough. The battery test should
always be completed before performing other diagnostic
tests.
General specifications given in this manual are for 6–12 volts
systems and give satisfactory performance references for most
vehicles. However, there are some vehicles which will require
the actual vehicle manufacturer’s service specification values for
more accurate test conclusions.
When hooking up the analyzer, always do the following steps:
1. Be sure the load knob is turned to OFF before connecting
the analyzer cables to the battery. Take note of the safety
precautions on the front page of this manual.
2. Connect the analyzer Battery Clamps to the battery terminals;
Red to positive (+), Black to negative (-) They may be reversed
to get a minus volts reading. The clamp jaw from each cable
must have a solid connection to the battery terminal to assure
good voltage measurements and to prevent arching during
adapter attachment or high current load testing.
3. Set the volts (source) selector to Battery Volts. The analyzer
will show the battery voltage. The display will work from ±4.0
to ±16.0 volts so that 6 to 12 volt batteries can be tested.
4. With the Amps Probe jaws closed and not around any wires,
switch to the “1000A” position and push the Zero Amps Knob
until the Amps Display reads “000”.
NOTE
This manual assumes that Negative Ground battery systems
are being tested since Positive Ground batteries exist only
on antique or unusual vehicles. This affects the circuit
troubleshooting procedures.
BATTERY CAUTION
1. Always wear safety glasses when working around batteries.
2. Do not break live circuits at the battery terminals.
3. Avoid accidentally shorting the insulated battery terminal to
any ground metal. Never put a wrench on a live battery
terminal. Severe burns may result. Always disconnect the
battery chassis ground cable first.
BATTERY TESTING
The battery test has three steps:
I. Visual Inspection
II. State of Charge Check
III. Load Test
A battery must be tested with a load to determine its ability to
perform. Specific gravity or open circle voltage tests do not com-
pletely gauge a battery’s performance.
Sealed batteries can be tested like open vent batteries except for
the specific gravity test.
VISUAL INSPECTION
1.
Corroded or damaged cable connectors.
2. Loose or damaged battery posts.
3. Damaged battery cases which allow the loss of electrolyte.
4. The battery fluid must completely cover the cell plates in all
cells. If water is added to the battery before specific gravity