TM-5-2330-378-14-P

SEMITRAILER, LOWBED: 40 TON CONSTRUCTION EQUIPMENT TRANSPORTER M870 AND M870A1

TECHNICAL MANUAL; OPERATOR'S, UNIT, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST)

JUNE 1999

TM-5-2330-378-14-P - Page 100 of 524

TM 5-2330-378-14&P

4-16. TROUBLESHOOTINGCHART.

a. LIGHTS

(1) NO TRAILER LIGHTS WORK (M87

Initial Setup:

Tools/Test Equipment:

- Parking brake applied (see operator's manual

• Tool kit, general mechanic's:

automotive

fortowing vehicle).

(item 7, Appendix B)

- Wheels chocked (para 2-10).

• Multimeter (item 8, Appendix B)

Equipment Conditions:

-Semitrailer coupled to towing vehicle. Engineoff

(see operators

manual for towing vehicle).

WARNING

ALWAYS

make sure all electrical power

is disconnected

before performing

any

maintenance

on the electrical

system.

Serious injury ordeath may occur ifsafety

precautions

are not observed.

A.

Turn on towing vehicle service lights. Set multi-

meter at 30 V dc. Place red probe on socket pins

of towing

vehicle

intervehicular

connector

socket, and ground black probe.

Does meter reading show low or no voltage?

24-VOLT

Troubleshoot

towing

vehicle

(refer

to

ro

u

oot

t

tor@

sm

[operator's

manual for towing vehicle). Verify

u@

p

pro

m is

sol

roblem is solved.

B.

Hook up intervehicular cable connector (1). Set

multimeter

at 30 V dc.

Place red probe on

connector

socket

at

semitrailer

end of

intervehicular

cable, and ground black probe.

12-VOLT

L.141;10.

Does multimeter

show any voltage?

I

continued

on

next

page

4-12