CEN-TECH 3-PIECE SET Owner's Manual & Safety Instructions page 3

Operation
Read the ENTIRE IMPORTANT SAFETY INFORMATION section at the beginning of this
document including all text under subheadings therein before set up or use of this product.
Note: Your Circuit Tester comes completely
assembled. It is important that you read the
entire manual to become familiar with the
product BEFORE you use the Circuit Testers.
The 3 Piece Circuit Tester Set contains each of the
following Circuit Testers:
Self-Powered Electrical Continuity Tester. Use
this tester to test for continuity with the power
disconnected. For use on recreational and general
automotive vehicles.
Note: This Tester requires one "AA" battery.
1. Disconnect the vehicle battery.
2. Attach the Alligator Clip (12A) to a ground of
the vehicle, such as the vehicle's body.
3. Poke the tip of the Probe (1A) through the
wire's jacket and touch the metal of the wire.
If the circuit is complete, the Bulb (7A) will
illuminate; this indicates there is electricity
flowing through the circuit. No illumination of
the bulb indicates no electricity flowing through
the circuit and that repair or replacement of
the components being tested is needed.
Heavy Duty Circuit Tester (Green) for 18, 24,
and 36 Volt systems. Use this tester to check AC
or DC wiring up to 36 Volts. Use to check series-
parallel switches and solenoid on tractor-trailer starter
systems.
Note: Use this tester with the battery connected.
The vehicle does not have to be running.
Changing the Bulb
For Tester A and Tester B:
1. Unscrew the Probe Base from the Handle.
2. Remove the Spring.
3. Unscrew the Bulb from the Bulb Socket.
4. Screw a new Bulb into the Bulb Socket.
5. Screw Probe Base and Handle back together.
Item 63612 For technical questions, please call 1-888-866-5797.
1. Connect the Alligator Clip (11B) to the vehicle as a
ground; or connect it to the negative battery post.
2. Poke the tip of the Probe (1B) through the
wire's housing and touch the metal of the wire.
If the circuit is complete the Bulb (6B) inside
the Handle (7B) will illuminate; this indicates
there is electricity flowing through the circuit.
No illumination of the Bulb (7B) indicates no
electricity flowing through the cirecuit and
that repair or replacement of the components
being tested is needed.
High and Low Voltage Tester. Use this tester to
check primary circuits of 6 and 12 Volts. Use to
trouble shoot both primary and secondary circuits.
On secondary or high voltage circuits you can check
spark plugs or distributor caps.
Note: To test spark plugs and secondary
(ignition) circuit, do not ground clip.
1. Attach clip to nose of probe housing.
2. With engine idling, run probe of tester
along wire from distributor to plugs.
3. To test plugs, insert probe through plug cap.
Extreme brightness of long bulb flashes is
sign of high resistance or plug gap is set
too far apart. Bright even flashes indicate
normal ignition. Extreme dimness indicates
low resistance and means carbon deposits
have formed on plug electrodes or plug is not
firing properly for other reasons. Remove
plug for closer check after cleaning.
For Tester C:
1. Unscrew the Probe Base (2C) from
the Handle (black) (9C).
2. Unscrew the Bulb (low voltage) (6C) from
the Bulb Socket (3C) and Spring (5C).
3. Remove the Fuse from the Spring
(7C) and Handle (9C).
4. Replace Bulb (6C) and Fuse (high voltage).
5. Reconnect Probe Base (2), Handle
(9) with Springs (5/7).
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