0586251 JOHNSON SWITCH ASSY., Trim & tilt

Initial Troubleshooting Procedure
Check The Resistance In Excitation Circuit. This step is only for alternators with external excitation when the terminal for excitation is labeled: "1", "REG" and "D+". See "Alternator Specifications" if the method of excitation is unknown. Go to Step 3 if your alternator is self-excited. If the alternator terminal for excitation is labeled with "IG", go to Step 2 .
If the generator set is equipped with a disconnect switch, then turn the disconnect switch to the ON position.
Verify voltage at the excitation terminal. Connect the red lead from a multimeter to the excitation terminal. Connect the black lead to a ground source. The ground source is the alternators case ground.
Read the voltage that is shown on the multimeter.Expected Result: The voltage reads at least 0.2 V.Results:
OK: The voltage reads 0.2 V or more. The excitation circuit is correct. Proceed to Step 3.
NOT OK: The voltage is less than 0.2 V. There is a fault in the wiring harness to the alternator or there is a poor electrical connection. Correct the problem. Watch for a recurrence of the problem.
Check The Resistance In Excitation Circuit.This step is only for alternators with external excitation when the terminal for excitation is labeled: "IG". See "Alternator Specifications" if the method of excitation is unknown. Go to Step 3 if your alternator is self-excited.
Turn the disconnect switch to the ON position.
Verify voltage at the excitation terminal. Connect the red lead from a multimeter to the excitation terminal. Connect the black lead to ground.
Read the voltage that is shown on the multimeter.Expected Result: The voltage is within 0.5 V of the battery voltage.Results:
YES: The voltage reads battery voltage. The excitation circuit is correct. Proceed to Step 3.
NO: The voltage is not within 0.5 V of the battery voltage. There is a fault in the wiring harness to the alternator or there is a poor electrical connection. Correct the problem. Watch for a recurrence of the problem.
Check The System Voltage.
Before you start the generator set, connect a voltmeter between the "B+" terminal and the case of the alternator. Disconnect all loads from the battery. Disconnect the battery voltage to the EMCP II+.
Turn the disconnect switch to the ON position but do not start the engine.Expected Result: This voltage should be system voltage.Results:
YES: The voltage is system voltage. Go to Step 4.
NO: The voltage is less than system voltage. Verify that the batteries are good and verify that battery connections are good. Go to "T4Alternator Drive System - Check" if the batteries are good.
Perform The Initial Check Of Alternator Operation.
The voltmeter remains connected in the configuration from Step 3.
Start the engine. Set the throttle to at least 75%. Read the voltage on the voltmeter.Expected Result: The voltage is higher than the voltage recorded in the previous Step 3. Results:
YES: The voltage is higher than the voltage observed in the previous Step 3. The voltage is also lower than the maximum voltage that is listed in the specifications for the alternator. The alternator is partially charging the battery. See the following diagnostic flow chart for reference in continued testing. Proceed to "T1 Alternator Output - Test".
YES: The voltage is higher than the voltage observed in the previous Step 3. The voltage is also higher than the maximum voltage that is listed in the specifications for the alternator. The alternator is over charging. Proceed to "T 8 Alternator Overcharging - Test".
NO: The voltage is not higher than the voltage which was observed in Step 3. Proceed to "T4 Alternator Drive System - Check".Note: Severely discharged batteries can cause low system voltage. Severely discharged batteries can occur even while the engine is running above idle, and the alternator is working properly. Proper low engine idle is also important. Most of the alternators in Caterpillar applications are self-excited. These alternators must exceed a turn-on speed before charging will begin. Alternator output can be low at idle.
Illustration 1 g00508188
T1 Alternator Output - Test
Ensure that the batteries are NOT fully charged.
Fully charged batteries have open circuit voltage of 25 V on 24 V systems.
If the batteries are fully charged, then crank the engine for 30 seconds. This action reduces the battery voltage. Operate the lights for 10 minutes while the engine is off as an alternative.
Connect the 9U-5795 Current Probe to a DMM (digital multimeter) or use a 225-8266 Ammeter Tool Gp . The multimeter must have a peak hold feature. Clamp the probe around alternator output wire ("B+"). Before you clamp the probe around the wire, ensure that the probe is "zeroed".
Set the digital multimeter to "peak hold" or "max mode" on the "mV" scale.
Start the engine, and immediately set the throttle to at least 75%. The peak current will appear on the voltmeter in "peak hold" or "max" mode. Expected Result: This current reading should be at least 90% of the specified peak output. Results:
OK: The current is at least 90% of the specified peak output. See "Alternator Specifications" for exact numbers. Go to "T2 Electrical System Current - Test".
NOT OK: The current is less than 90% of the specified peak output. Go to "T4 Alternator Drive System - Check".T2a - Test For Generator Set Equipped With A Main Disconnect Switch
Turn off all of the accessories. Also, disconnect the battery supply voltage to the EMCP II+.
Clamp a 9U-5795 Current Probe or 225-8266 Ammeter Tool Gp around the main ground cable. Clamp the tool with the positive side away from the battery. Reset the probe (zero) before you clamp the probe around the wire. Read the current. Expected Result: The current is below 2 A.Results:
YES: The current is below 2 A. Continue to Step 3.
NO: The current is above 2 A. There is a current draw in the system. Go to "T5 Alternator Current - Test".
Turn the disconnect switch to the ON position. Connect a multimeter across the disconnect switch terminals. Connect the red lead to the terminal on the frame side. Connect the black lead to the terminal on the battery side. Use the 10A connections in order to avoid