Ground Test

TM 10-3930-631-34

h. Check the seat switch to assure that it closes

CAUTION

when the seat is depressed.

Make certain capacitors are discharged before

i. Inspect all contactors to assure that there is no

beginning the following tests.

interference to operation and that the units

have

a. Set multimeter on low ohms scale. Connect

satisfactory overtravel. The microswitches on the

one lead from meter to frame of lift truck at location

contactors should operate when the normally open

where paint will not insulate the frame. Touch other lead

contacts close.

to another good ground point on frame to assure that

j. Inspect contactor tips for wear. If the contacts

proper ground connection has been obtained. Meter

are worn to the point where copper is showing through

readings should be zero. If zero reading is not obtained,

in the contact area, replace the contactor tips (TM 10-

check calibration of meter by connecting the two leads

3930-631-12).

together.

k. Clean all electrical components and elec- trical

b. With the key switch in the ON position, and

component compartments with an industrial type vacuum

multimeter set on high ohms scale, connect one lead of

cleaner. Remove all foreign material or objects from all

the meter to a good ground on the frame. Touch the

compartments.

second lead of the meter first to one pole and then to

I. Use a volt-ohm-milliometer (VOM) with a 20,000

the other pole of the battery receptacle that is mounted

ohms-per volt direct current sensitivity and 6,000 ohms

on the left side of the lift truck frame. Resistance

per-volt alternating current sensitivity.

readings must be greater than 50,000 ohms.

m. A jumper wire, approximately 18 inches (456.2

CAUTION

mm) long with alligator clips on each end should be

This is the receptacle (fig.

9-5) that is

used.

permanently mounted on the lift truck, not the

9-6. Ground Test

connector on the cables from the battery.

Figure 9-5. Battery Cables and Receptacle.

9-9