C.E. Niehoff & Co. N1245/N1248-3 Troubleshooting Guides - Manual (Page 8)

Page 8 TG44D
If you have questions about your alternator or any of these test procedures, 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 C: Advanced Troubleshooting
(CONT’D)
Yes No
Alternator is defective.
Unplug alternator-to-regulator harness from regulator. Connect red lead from DMM to socket A in plug.
Connect black lead to socket B in plug. Does resistance read 1.5 ± 0.2 ohms?
Yes No
Replace existing regulator with known good regulator.
Run engine. Does OVCO trip?
Alternator is defective. Original regulator is
defective.
 
Yes No
With red lead from DMM connected to socket A in plug, connect black lead to B– terminal. Does
resistance read OL (out of limits)?
Alternator is defective.




Figure 8 – Alternator-to-Regulator Harness Plug
Chart 3 – No Alternator Output – Test OVCO Circuit – N3044 or N3261 Regulator
CONNECTIONS
A F–
B F+/D+
C B–
D B+
E Phase