Suzuki Burgman 400 - Service manual > Electrical Circuit Inspection Procedures

While there are various methods for electrical circuit inspection, described here is a general method to check for open and short circuit using an ohmmeter and a voltmeter.

Open circuit check

Possible causes for the open circuits are as follows. As the cause can exist in the connector/coupler or terminal, they need to be checked carefully.

• Loose connection of connector/coupler
• Poor contact of terminal (due to dirt, corrosion or rust, poor contact tension, entry of foreign object, etc.)
• Wire harness being open
• Poor terminal-to-wire connection

When checking system circuits including an electronic control unit such as ECM, etc., it is important to perform careful check, starting with items which are easier to check.

1) Disconnect the (-) cable from the battery.

2) Check each connector/coupler at both ends of the circuit being checked for loose connection. Also check for condition of the coupler lock if equipped.

1. Sensor

    "A": Check for loose connection.

3) Using a test male terminal, check the female terminals of the circuit being checked for contact tension.

Check each terminal visually for poor contact (possibly caused by dirt, corrosion, rust, entry of foreign object, etc.). At the same time, check to make sure that each terminal is fully inserted in the coupler and locked.

If contact tension is not enough, rectify the contact to increase tension or replace. The terminals must be clean and free of any foreign material which could impede proper terminal contact.

    "B": Check contact tension by inserting and removing.
    "C": Check each terminal for bend and proper alignment.

4) Using continuity inspect or voltage check procedures as described below, inspect the wire harness terminals for open circuit and poor connection.

Locate abnormality, if any.

    "D": Looseness of crimping
    "E": Open
    "F": Thin wire (A few strands left)

Continuity check

1) Measure resistance across coupler "B" (between "A" and "C" in figure).

If no continuity is indicated (infinity or over limit), the circuit is open between terminals "A" and "C".

2) Disconnect the coupler "B" and measure resistance between couplers "A" and "B-1".

If no continuity is indicated, the circuit is open between couplers "A" and "B-1". If continuity is indicated, there is an open circuit between couplers "B-2" and "C" or an abnormality in coupler "B-2" or coupler "C".

Voltage check

If voltage is supplied to the circuit being checked, voltage check can be used as circuit check.

1) With all connectors/couplers connected and voltage applied to the circuit being checked, measure voltage between each terminal and body ground.

2) If measurements were taken as shown in the figure below and results are as listed in the following, it means that the circuit is open between terminals "A" and "B".

Voltage between
"A" and body ground: Approx. 5 V
"B" and body ground: Approx. 5 V
"C" and body ground: 0 V

3) Also, if measured values are as listed in the following, a resistance (abnormality) exists which causes the voltage drop in the circuit between terminals "A" and "B".

Voltage between
"A" and body ground: Approx. 5 V
"B" and body ground: Approx. 5 V - 2 V voltage drop
"C" and body ground: 3 V - 2 V voltage drop

Short circuit check (Wire harness to ground)

1) Disconnect the (-) cable from the battery.

2) Disconnect the connectors/couplers at both ends of the circuit to be checked.

NOTE If the circuit to be checked branches to other parts as shown, disconnect all connectors/ couplers of those parts. Otherwise, diagnosis will be misled.

3) Measure resistance between terminal at one end of circuit ("A" terminal in figure) and body ground. If continuity is indicated, there is a short circuit to ground between terminals "A" and "C".

    "D": To other parts
    "E": Other parts

4) Disconnect the connector/coupler included in circuit (coupler "B") and measure resistance between terminal "A" and body ground. If continuity is indicated, the circuit is shorted to the ground between terminals "A" and "B".

    "D": To other parts

Using the Multi-Circuit Tester

• Use the Suzuki multi-circuit tester set.
• Use well-charged batteries in the tester.
• Be sure to set the tester to the correct testing range.

Special tool (A): 09900-25008 (Multi-circuit tester set)

Using the tester

• Incorrectly connecting the (+) and (-) probes may cause the inside of the tester to burnout.
• If the voltage and current are not known, make measurements using the highest range.
• When measuring the resistance with the multi-circuit tester (1), ∞ will be shown as 10.00 MΩ and "1" flashes in the display.
• Check that no voltage is applied before making the measurement. If voltage is applied the tester may be damaged.
• After using the tester, turn the power off.

Special tool : 09900-25008 (Multi-circuit tester set)

NOTE

• When connecting the multi-circuit tester, use the needle pointed probe to the back side of the lead wire coupler and connect the probes of tester to them.
• Use the needle pointed probe to prevent the rubber of the water proof coupler from damage.

Special tool (A): 09900-25009 (Needle pointed probe set)

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