Voltage

KaptinAmerika

Well-Known Member
STARTER VOLTAGE DROP TEST

Attach the red meter lead to the positive post on the battery. Attach the black lead to the
component in the circuit (solenoid). Activate the starter and observe the meter reading.
The meter will read the voltage drop. Ideal voltage drop would be zero or have no drop at all. A typical circuit drop is less than 1 Volt. If voltage drop is greater, backtrack through the circuit until the source of the drop is found. This same test can be performed on the negative side also. Attach the black lead of the meter to the negative side of the battery and the red side to the ground you wish to check.

STATOR/ROTOR TEST

To check for a grounded stator, tum ignition OFF, and disconnect the regulator from the stator plug in the crankcase. Connect on Ohmmeter between the crankcase and either stator socket. There should be no continuity across either test point. Any other readings indicate a grounded stator which must be replaced.

RESISTANCE CHECK

Using an Ohmmeter, measured resistance across the stator plug should be between 0.1 to 0.2 Ohms. If resistance is lower, the stator is damaged, and must be replaced.

AC OUTPUT TEST

Disconnect the regulator and connect an AC voltmeter across both stator plugs. Run the engine to 2000 rpms. The AC output should read between 32-40 AC Volts (16-20 per
1000 rpms). If the output is below specifications, a charging problem has occurred and the stator/rotor needs to be replaced.
NOTE: Always recheck voltage output after making repairs.

VOLTAGE REGULATOR BLEED TEST

Regulator must be connected to the battery. Unplug the regulator from the stator, and using a light, touch one probe to a known good ground, and the other to the regulator pins, one at a time. If the light glows, replace the regulator.

CURRENT DRAW TEST

Using a load tester, place the induction pickup or current probe pickup over the negative battery cable. Disconnect the regulator from the stator and start the motorcycle. With the ignition and all continuously running lights turned ON (headlight on hi beam), read the total current draw. Compare this reading to that obtained in the CURRENT AND VOLTAGE OUTPUT TEST. The current output should exceed current draw by 3.5 amps, minimum. Reconnect the regulator.

CURRENT AND VOLTAGE OUTPUT TEST

Connect the load tester leads to the battery terminals. Place the induction pickup over the
positive regulator cable. Run the engine o 3000 rpms and increase the load to obtain a constant 13.0 volts. Current output should be 26-32 Amps.

VOLTAGE OUTPUT TEST

Remove load. Read the load tester voltage meter. Voltage to battery must never exceed
14.8 volts. If voltage is higher, replace regulator.

CURRENT DRAIN TEST

1. Ignition Key to the OFF position.
2. Remove seat.
3. Disconnect the ground(-) cable from battery negative (-) terminal.
4. Measure battery current using instructions provided with DMM.
5. Connect red(+) probe of the DMM to the ground cable and connect black(-) probe to negative(-) terminal of battery.
6. Current should read less than 2mA for Carbureted Models and less than 3.5mA
for EFI models. (EFI models will draw ~500mA for 15seconds when meter is first attached).
7. If an over current condition is found, locate the faulty component or harness by disconnecting one harness at a time, until current draw is within specifications. When current draw is within specifications, the last connection disconnected will be the circuit or
component affected. Use the electrical schematic to aid in fault location.

VOLTAGE REGULATOR

Do not disconnect the B+ wire from the circuit breaker and measure voltage to determine if the voltage regulator (VR) is faulty. The VR will not charge if there is no battery load (see Chapter 14, Troubleshooting). Follow the Charging System Flowchart to troubleshoot charging problems. The VR is grounded through the case, so the mounting bolts must be tight. Add this as a check on every bike that comes into your shop. Check and clean the VR mounting location whenever the VR has been removed from the motorcycle.

VR TEST PROCEDURE

Use the following flowcharts to determine if the charging system indicates a faulty VR.
Review the DMM users manual, as some resistance measurements may be over the
capability of the meter and show an "Open" or "OL," etc. This indicates a very high
resistance and should be considered >2MQ.
 
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