Subaru XT 1988 Service Manual page 1199

6-1 ENGINE ELECTRICAL SYSTEM
BRUSHES Ie REGULATOR
Measure the length of each brush. If wear exceeds the wear Connect a variable resistor, two 12·V batteries, a resistor and
limit, replace the brush. Each brush has the wear limit mark on voltmeter as shown below.
it.
Brush length:
Standard
18 mm (0.71 in)
Wear limit
6.0
mm
(0.236
in)
If the brush pigtail (lead wire) is soldered, use a soldering iron
heated to 300 to 350°C (572 to 662°F) and paste without
oxygen.
L6·373
Fig.
37
18
BAT2T
Fig. 38
Perform the following measurement:
Resistor (Rl):
10n/3W
Variable resistor (RV):
0-300n/12W
Battery (BATl & BAT2):
l2V
DC voltmeter:
0-50V
(measured Vl , V2,
V3 and V4)
L6·374
1) Check V1 (voltage of BA T1). The voltage must be 10 to
13V.
2) Check V3 (voltage of BAT1
+
BAT2). If a voltage of 20 to
26V is measured, both BAT1 and BAT2 are normal.
3) Measure V2 (voltage between terminals F and E) while
gradually moving the variable resistor away from O. Voltage
V2 should change from below 2.0V to voltage V1 measured in
step 1) above. If no change is observed, the regulator is faulty,
and must be replaced with a new one.
4) Measure V4 (voltage between the intermediate tap of
variable resistor and terminal E) with variable resistor RV
fixed to see whether the voltage is within the specified range.
If found within the range, the regulator is normal. If out of
range, replace the regulator with a new one.