John Deere stx38 - Manual (Page 138)

4 - 54
3/21/97
CIRCUIT OPERATION AND DIAGNOSIS ELECTRICAL
PTO CIRCUIT DIAGNOSIS POINTS
STX30 & STX38 (SN —210000)
Test Conditions:
• Transaxle in neutral • Key switch in run position
• Park brake engaged • Meter negative (-) lead on battery negative (-)
terminal
• PTO switch ON (engaged) • Meter positive (+) lead on numbered test point
Test/Check Point Normal If Not Normal
1. Battery positive terminal. 11.8—13.2 volts Test battery
2. Key switch terminal B. Battery voltage Check battery cable connection,
fusible link or circuit breaker and
200/210 red wires.
3. Key switch terminal A. Battery voltage Replace key switch.
4. PTO switch—yel wire. Battery voltage Test 510 yellow wire.
5. PTO switch—blue wire. Battery voltage Replace PTO switch.
6. PTO clutch—yel wire. Battery voltage Test 750 blue wire.
Test Conditions:
• Key switch in off position
Test/Check Point Normal If Not Normal
7. PTO clutch—blk wire. Maximum 0.1 ohms Check PTO clutch ground circuit—
120 blk wire, engine, frame, and
battery negative cable ground
connection.
8. PTO clutch PTO clutch air gap
Warner—0.38—0.64 mm (0.015—
0.025 in.)
Ogura—0.30—0.51 mm (0.012—
0.020 in.) Adjust air gap to 0.51 mm (0.020
in.) .
If air gap OK, replace PTO clutch.