Yamaha EF4500iSE Theory & Diagnostics Manual page 44

Yamaha Generator Theory & Diagnostics Guide
TROUBLESHOOTING PROCEDURES
FOR AVR TYPE GENERATORS
The troubleshooting procedure starts out exactly the
same way as with the non-AVR type.
First check the engine speed, especially if the prob-
MAIN COIL RESISTANCE TEST
lem is slightly low voltage. Adjust if out of specifica-
tion.
Br R
Turn on the AC protector and check the voltage out-
put at the receptacle. Continue on to the next step if
it is out of specification.
Check the voltage at the generator unit. Remember,
if the voltage is OK there, but not at the receptacle,
then it is a wiring or control box problem. And if it is
not OK there, then the problem is in the generator
unit.
As with the non-AVR type, perform the normal resis-
tance test, short to ground test and the shorted
together test on all of the coils.
SUB-COIL RESISTANCE TEST
Be sure to reference the proper Service Manual for
the model you are working on for specifications and
wiring color codes.
Disconnect all of the coils at the connectors.
Start with the resistance test on the Main Coil, the
sub-coil resistance test,
ExCITER FIELD COIL RESISTANCE TEST
and the Exciter Field Coil resistance test, which is
the two pin connector with the black and white
wires.
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