MarelliMotori MARK V Manuel Utilisateur page 36

#2 - VISUAL / MULTI-METER CHECKS
CHECK F Thyristor
Visual inspection
:
Check that the thyristor shown in the
-
figure is not damaged.
Possible damage types are:
a) Thyristor is blown.
b) Thyristor in broken.
Multi-meter check
:
1- In the multi-meter, select the diode
measurement mode.
2- Connect the multi-meter
terminals - and 0 of the AVR.
Expected values are:
COM probe on 0: 0.8 to 0.9V.
COM probe on -: open (OL).
If any of the above measurements is not met, the thyristor is damaged.
Check result
:
If the result of all the above checks is positive, tick the ok box in section #2 of the report form,
-
Check F.
Otherwise leave the box blank.
In case of component failure:
Possible effects on regulation
The alternator output voltage is lower than the rated voltage and equal to the residual one.
-
You cannot set the proper value using the VOLT trimmer.
The alternator output voltage is higher than the rated voltage.
-
You cannot set the proper value using the VOLT trimmer.
Possible failure causes
Mechanical damage caused by impact/shock.
-
Improper connection on terminals 0 and -.
-
Short circuit between terminals + and -.
-
Not enough contact between the AVR terminals and the FASTON connectors, resulting in sparks
-
and voltage peaks.
Actions
:
Replace the AVR.
-
963857121_M
probes to
:
:
Mark V M16FA655A
EN
Marelli Motori
36