C.E. Niehoff & Co. C633 Troubleshooting Guides - Manual (Page 6)

Page 6 TG80A
Chart 3 – No 14 V Alternator Output – Test Circuit
Figure 6 – Phase Connection 3-Pin Harness Plug
PIN CONNECTIONS
A Phase P1
B Phase P2
C Phase P3
Shut off engine. With key off, engine off: Test for battery voltage of 14 V output terminal on
regulator. Does +14 V battery voltage exist?
Yes No
Repair vehicle wiring as necessary.
Yes
Set DMM to diode tester. Connect red lead of DMM to
socket C of regulator harness plug and black lead to
each phase pin in phase harness plug. Meter should
show voltage drop value.
Then reverse meter lead connections. Meter should
show OL (blocking).
No
Figure 5 – Alternator-to-Regulator 4-Socket Harness Plug
SOCKET CONNECTIONS
A F–
B Phase Signal AC
C B–
D 28 V B+
If you have questions about your alternator or any of these instructions, or if you need to locate a Factory Authorized Service Dealer, please contact us at:
C. E. Niehoff & Co.• 2021 Lee Street • Evanston, IL 60202 USA
TEL: 800.643.4633 USA and Canada • TEL: 847.866.6030 outside USA and Canada • FAX: 847.492.1242
E-mail us at [email protected]
Section E: On-Vehicle No 14 V Output Troubleshooting
Alternator is defective. Regulator is defective.