ELECTRICAL SYSTEM 273

2. Disconnect the altemator 3-pin connector con-taining 3 yellow wires (Figure 10).

3. Use an ohmmeter set at R x 1 and measureresistance between each yellow wire (Figure 10) onthe altemator side of the connector. Table 2 lists thespecified stator coil resistance.

4. If there is continuity (indicated resistance) and itis within the specified resistance, the stator coil isgood. If there is no continuity (infinite resistance) orthe resistance is higher than specified, the coil isdamaged. Replace the stator assembly.

5. Use an ohmmeter set at R x 1 and check continu-ity from each yellow wire on the altemator stator sideof the connector to ground.

6. Replace the stator coil if any yellow terminalshows continuity (indicated resistance) to ground.Continuity indicates a short within the stator coilwinding.

NOTEBefore replacing the stator assembly,check the electrical wires to and withinthe electrical connector for any opensor poor connections.

1. If the stator coil (Figure 11) fails either of thesetests, replace it as described under Left CrankcaseCover and Stator Coil (TRX300EX) in Chapter Five.8. Apply a dielectric grease to the electrical connec-tor before you reconnect it. This will help seal outmoisture.9. Make sure the electrical connector is free ofcorrosion and properly connected.

ALTERNATOR AND AC LIGHTINGSYSTEM

(TRX250X)

Exciter Coil Inspection

1. Disconnect the exciter coil black/red electricalconnector (Figure 12).2. Use an ohmmeter set at R x 100 and measureresistance between the black/red connector on thealtemator stator side of the connector and ground.Table 1 lists the specified exciter coil resistance.3. If the resistance is as specified, the exciter coil isgood. If there is no continuity or if the resistance ishigher than specified, the coil is damaged and thestator assembly must be replaced.

NOTEBefore replacing the stator assembly,check the electrical wires to and withinthe electrical connector for any opensor poor connections.

4. If the exciter coil (Figure 12) fails either of thesetests, replace the stator assembly as described underLeft Crankcase Cover and Stator Coil (TRX250X) inChapter Five.5. Apply a dielectric grease to the electrical connec-tor. This will help seal out moisture.6. Make sure the electrical connector is free ofcorrosion and properly connected.

Lighting Coil Testing

1. Disconnect the lighting coil 2-pin connector con-taining one green and one white/yellow wire (Figure12).2. Use an ohmmeter set at R x 1 and check resis-tance between the green and white/yellow connec-tors on the altemator stator side of the connector.Table 1 lists the specified lighting coil resistance.3. If resistance is as specified resistance, the lightingcoil is good. If there is no continuity (infinite resis-

274 CHAPTER NINE

tance) or if the resistance is higher than specified, thecoil is damaged. Replace the stator coil and retest.

NOTEBefore replacing the stator assembly,check the electrical wires to and withinthe electrical connector for any opensor poor connections.

4. If the lighting coil (Figure 12) fails either of thesetests, replace the stator assembly as described underLeft Crankcase Cover and Stator Coil (TRX250X) inChapter Five.5. Apply a dielectric grease to the electrical connec-tor prior to reconnecting it. This will help seal outmoisture.6. Make sure the electrical connector is free ofcorrosion and properly connected.

AC Regulator Test

The AC regulator (Figure 13) is mounted at thefront, left side of the vehicle.1. Voltage test: Perform the following:

a. Find the 4-pin electrical connector containingthe following wires colors: green, brown,white/yellow and green/black. Then removethe rubber protector from the 4-pin connector,but do not disconnect the connector.

b. Connect a voltmeter between the white/yellowand green terminals in the 4-pin connector.

c. Start the engine and read the voltmeter scalewhile slowly increasing the engine speed. Thevoltmeter must read 12.5-13.5 volts.

d. The AC regulator must prevent any furtherincrease in voltage. If the voltage increases

STATOR ASSEMBLY (TRX250X)

Wiring connectors

Grn

Grn

Lightingcoii

BIk/red

V

Wht/yeiBik/red

Excitercoii

ELECTRICAL SYSTEM 275

above the specified amount, check for loose orcorroded electrical connectors at the AC regu-lator connector.

2. Resistance test: Perform the following:

a. Disconnect the AC regulator 2-pin connectorcontaining one green wire and one white/yel-low wire (Figure 13).

b. Use an ohmmeter set at R x 1 and checkcontinuity between the green and white/yel-low wires on the wiring hamess side, not onthe AC regulator side. The ohmmeter mustread infmity.

3. If the resistance reading is correct, but the voltagereading is incorrect, replace the AC regulator. Ifvoltage reading is correct, but the resistance readingis incorrect, check the wiring hamess for short oropen circuits and for dirty or loose-fitting connectorterminals.

4. Reconnect the AC regulator 2-pin connector.

5. Slide the mbber protector over the 4-pin connec-tor.

AC RegulatorRemoval/Installation

1. Disconnect the AC regulator 2-pin connector(Figure 13).

J3) AC REGULATOR (TRX250X)

AC reguiator

2 pinconnector

Hoider Wiringiiarnessconnector

2. Remove the nut and bolt securing the AC regula-tor to its holder, and then remove the AC regulator(Figure 13).3. Install by reversing these removal steps.

IGNITION SYSTEM(TRX250X)

All models are equipped with a capacitor dis-charge ignition system.

Figure 14 shows a schematic of the ignition sys-tem.

CDI Precautions

You must take certain measures to protect thecapacitor discharge system when testing and work-ing on it.1. Never disconnect any of the electrical connec-tions while the engine is mnning.2. Apply dielectric grease to all electrical connec-tors prior to reconnecting them. This will help sealout moisture.3. The electrical connectors must be free of corro-sion and properly connected.4. The ignition control module unit is mounted in arubber mount. If you remove the ignition controlmodule unit, make sure to reinstall it into the rubbermount.

CDI Troubleshooting

Refer to Chapter Two.

CDI UnitWiring Harness Test

1. Disconnect the 2-pin and 4-pin electrical connec-tors from the CDI unit (Figure 15).

NOTEWhen performing the following tests,connect the test probes between the con-nector terminals on the wiring harnessside of the connector', not on the moduleside.

2. Check the ignition switch line as follows:a. Switch an ohmmeter to R x 1.