Caution – C.E. Niehoff & Co. C653/C653A/C625 Troubleshooting Guides User Manual
Page 11
Page 11
TG13G
Self-energized alternator may have lost magnetism. Touch steel tool
to shaft to detect any magnetism. Is shaft magnetized?
Momentarily (1 sec.) jumper D+ terminal on regula-
tor to B+ terminal on alternator. Touch shaft with
steel tool to detect significant magnetism. Is shaft
magnetized?
Yes
No
Yes
No
Figure 10 – Alternator-to-Regulator Harness Plug
Chart 5 – No Output
Install a jumper from B+ terminal on alternator to
pin F in harness plug. Momentarily (1 sec.) jumper
pin A to B– terminal on alternator. Touch shaft with
steel tool to detect significant magnetism. Is shaft
magnetized?
Yes
No
PIN CONNECTIONS
Pin A
F–
Pin B
Phase
Pin C
B–
Pin D
B+
Pin E
D+
Pin
F
F+
Set DMM to diode test. Connect black lead of DMM
to pin E in harness plug. Connect red lead to B+
terminal on alternator. DMM should read OL. Reverse
leads. DMM should also read OL.
Unplug alternator-to-regulator harness. Connect
DMM across pin D and pin C in harness plug.
Does battery voltage exist?
Yes
No
Alternator is defective.
Yes
No
Alternator is defective.
Alternator is defective.
Regulator is defective.
Install a jumper from B+ terminal on alternator to
pin F in harness plug. Momentarily (1 sec.) jumper
pin A to B– terminal on alternator. Touch shaft with
steel tool to detect significant magnetism. Is shaft
magnetized?
Yes
No
Alternator is defective.
Regulator is defective.
Remove jumper from D+ to B+.
When conducting this step,
ensure that the probes do not
touch other pins, as an arc
may damage the wiring in the
harness.
CAUTION
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 E: C653 w/A2-338 Advanced Troubleshooting
(CONT’D)