Model

AC Electric Motors

AC Motor Type

The traction motor is a brushless, 3-phase, variable speed AC motor.

The AC motor has a rotor (in place of the DC armature) and a stator (in place of the DC field). There is no electrical connection to the rotor; current is induced in the rotor. The stator has three windings staggered 120° apart, and three external connections labeled U, V, and W. See Figure5-3 and Figure5-4 .

Shorted Winding

If the AC motor fails with a shorted winding, the motor speed fluctuates up and down, as if hunting/searching, and there is a high-pitched sound.

Using a clamping ammete r, measure current in each of the motor power cables. The shorted phase reads significantly higher than the other two phases.

Open Winding

If the AC motor fails with an open winding, the motor moves erratically, as if hunting/searching, and there is a ticking sound. Rotation is much slower than normal.

Using a clamping ammeter, measure current in each of the motor power cables. The open phase reads significantly lower than the other two phases.

Publication: 1146947, Revised: 12 Jan 2017

Section 5.Troubleshooting

Hydraulic Troubleshooting Guidelines

Hydraulic Troubleshooting Guidelines

When you measure the voltage at the solenoids, make sure the hydraulic lines and components are fully installed.

Use an ohmmeter to measure wiring continuity to solenoids. Use an ammeter to measure for the correct current to the solenoids and contactor coils.

Unless otherwise directed, disconnect the battery connector when you examine electrical circuits or components with an ohmmeter. Electrical current can damage the ohmmeter.

Visually inspect all hydraulic lines and components for:

•Leaking connections or connectors

•Loose or broken fittings

•Damaged tubing, hoses, vents, or seals

Inspect the hydraulic system for the correct pressure and that the relief valve is functioning correctly.

Check the hydraulic reservoir fluid level. If necessary, add fluid; fill to the oil fill line on the reservoir. See “Lubrication Equivalency Chart” on pageA-2.

NOTE: Always check hydraulic fluid level with forks fully lowered and when hydraulic fluid is cold.

Cap any open hydraulic lines to prevent contamination.