L: Charge System Warning Never/Always ON

L1 Check For Charging System Warning
- Check for charging system warnings to determine if the warning is always on or never on.

Is warning always on?

Yes
GO to L2
No
GO to L8

L2 Check For Open 'A' Circuit
- Measure voltage at test point 'A', Circuit 35 (O/LB) on the voltage regulator.

Is voltage at test point 'A' equal to battery voltage?

Yes
GO to L3.
No
CHECK ALTERNATOR (30A) fuse in Circuit 35 (O/LB) and REPLACE if required. If OK, SERVICE open in Circuit 35 (O/LB).

L3 Check For Open 'I' Circuit
- Disconnect three-pin voltage regulator connector C154.
- Turn ignition switch to RUN.

Is indicator lamp on?

Yes
SERVICE short to ground in Circuit 904 (LG/R).
No
GO to L4

L4 Check 'S' Circuit Function
- Connect voltage regulator connector C154.
- Remove one-pin 'S' connector C153.
- Connect wiring harness 'S' terminal, Circuit 4 (W/BK) to the positive (+) battery post using a jumper wire.

Is indicator lamp on?

Yes
REMOVE jumper wire. GO to L5.
No
REMOVE jumper wire. GO to L6.

L5 Check For Open 'S' Circuit
- Remove three-pin voltage regulator connector C154.
- Measure wiring resistance between the one-pin 'S' connector C153 and the 'S' (center) pin of the generator regulator connector C154.

Is resistance greater than 1 ohm?

Yes
SERVICE open or high resistance in Circuit 4 (W/BK).
No
CHECK for loose or bent pin in voltage regulator or connector. If OK, REPLACE voltage regulator.

L6 Check Stator Output Voltage
- Start engine.
- Measure voltage at the 'S' terminal on the back of the generator.

Is voltage at least 112 of battery voltage?

Yes
GO to L7.
No
REFER to battery and charging system diagnosis.

L7 Check Generator Output Voltage

- Measure voltage at the B+ terminal on the back of the generator with the engine running at 2000 rpm and all accessories turned OFF.

Is voltage greater than 15.5 V?

Yes
REFER to battery and charging system diagnosis.
No
SERVICE voltage regulator.

L8 Check 'I' Circuit Voltage
- Disconnect three-pin voltage regulator connector C154
- Turn ignition switch to RUN.
- Measure voltage at wiring harness 'I' terminal, Circuit 904 (LG/R).

Is voltage greater than 0 V?

Yes
GO to L9
No
SERVICE open in Circuit 904 (LG/R).

L9 Check For Burned Out Lamp
- Connect wiring harness 'I' terminal, Circuit 904 (LG/R) to ground with a jumper wire.

Is indicator lamp on?

Yes
REMOVE jumperwire. GO to L10.
No
REPLACE lamp or SERVICE high resistance in lamp socket or Circuit 904 (LG/R).

L10 Check For Poor Grounds
- Check for poor ground connections between voltage regulator and generator, generator and engine, or engine and battery.

Are all ground connections clean and tight?

Yes
GO to L11.
No
CLEAN or SERVICE grounds as required.

L11 Check 'S' Circuit Wiring
- Remove one-pin 'S' connector C153 from generator.
- Measure voltage at wiring harness 'S' terminal, Circuit 4 (W/BK).

Is voltage greater than 0 V?

Yes
SERVICE Circuit 4 (W/BK). Circuit should be hot only when engine is running. CHECK for swapped wires in voltage regulator connector.
No
GO to L12

L12 Check For Shorted Rectifier
- Measure voltage at the 'S' terminal on the back of the generator.

Is voltage greater than 1 V?

Yes
If lamp is on with one-pin 'S' connector C153 removed, REPLACE generator.
No
REPLACE voltage regulator.