Disassembly; Troubles - Repairs; Field Winding Test - Fiat 411 R Service Manual

< , . L Z ' l ' Z ' I l T l ; '
l
it
i
l
> . ' . ; . ~ . l . ' - 4 -
l
l
l l
l
1
c l
1
W . - w e . . . . e . - . - . l . . . . . . . . .
, , l ' l
l
l
l
l
I
l I
l
l
i
Field-winding resistance at 20°C (68° F) should be
7-<!.5 to 15,5 ohms, and may be measured between
termin ai 67 and ground, when generator is assembled.
Armature resistance at P0" C (63° F) is 0.520 to
0,545 ohm; it should be measured only exceptionally
to avoid damaging the commutator bars, owing to
the soldering of two pieces of wires spaced of 780".
Checking ohmic resistance.
Fig. 133. ~ Field winding test.
(Connect the measuring instrument ends to terminal 67 and
to ground).
Bisassembly.
Proceed as follows:
- remove the commutator head, disconnect terminal 67, unscrew and remove the through-bolts:
-» remove commutator end bracket and slide out the armature with the other bracket;
-— clamp armature in a lead-jaw vise and remove the drive pulley and the remaining bracket.
Troubles ~ Repairs.
Battery charging faulrs may be due to:
~1'auity generator;
- other trouble in the system.
Make sure to locate trouble first. The tell-tale lamp may furnish an indication with engine stopped or
running at different speed rates.
if the generator is faulty, the cause may be sometimes found elsewhere, and particularly in the regulator
group or in the circuits; "therefore. the operator should take care of generator efficiency and also check
the regulator §?oup and the whole system in order to prevent repetition of the generator trouble after its
reconditioning.
The battery charge spy lamp may be helpful to detect trouble. li when introducing the starting and lighting
key, and setting it'on position 1, the battery signal lamp remains lighted, the generator is normal; if
engine is being started and accelerated to a given speed, the light should go out. -
If, on the contrary, the lamp goes out only when engine has reached high speeds, the trouble may be
due to faulty windings (grounded or short circuited), or to the armature.
Generally, the higher the R.M.P. rate at which the charging begins, the higher the potential damage.
ll the lamp remains lighted, this indicates an interruption between the generator cables and the regulator
group; or shows that the group contacts are oxidized, and internal connections dissolclered; or that some
generator coil is interrupted, or completely grounded.
ii the above procedure leaves the light out and the trouble persists also after replacing the bulb this
signifies that the trouble is to be found between bulb holder and switch, or between switch and the con-
nections oi the components branched upon it.
When the battery indicator light goes out to go on again the engine speed being steady the fault is pro-
bably due to the regulator group or fuse or to' the electric connections (the jacks),
85
i
l
l
l
l
l
i
i s
§: