Service Manual
11
6
GLOW PLUG SYSTEM
KEYSWITCHES
Two types of keyswitches may be used on Briggs &
Stratton Daihatsu diesel engines.
Fixed Timer Preheat Keyswitch –
Part No. 493625
Keyswitch, Part No. 493625, is used with a preheat
timer and glow relay, Fig. 8. With the keyswitch in the
“On” and “Start” position, battery current is supplied to
the preheat timer and glow relay. See keyswitch
terminal positions and functions, Fig. 8.
See Fig. 78 and Fig. 79 at end of section, for wiring
diagrams for keyswitch No. 493625.
Fig. 8 – Keyswitch – Fixed Timer Preheat
1 + 3 + 6
2 + 4 +5
ON
OFF
START
2 + 5
NOT
USED
6
3
5
4
2
1
2
4
5
Accessory & Preheat Timer
Solenoid & Preheat Timer
Battery
6
3
5
4
2
1
ON
START
Test switch terminals for continuity with key-
switch in positions shown
NOTE: Terminals 1, 3, 6 Not Used
Manual Preheat Keyswitch –
Part No. 825129
The manual preheat keyswitch, Part No. 825129, is
equipped with four positions and six terminals, Fig. 9.
The “G1” terminal provides current to the glow plugs
only when the switch is in the “Heat” position. When the
keyswitch is turned to the “Start” position the “G2”
terminal provides current to the glow plugs while the
engine is cranking. See keyswitch terminal positions
and functions, Fig. 10.
Symbols are shown as they appear on rear of
keyswitch. Note that “B” terminal is connected to
terminal below it, Fig. 10. Keyswitch will not function
without connector.
Fig. 9 – Keyswitch – Manual Preheat
B+B+G1
B+B+M
ON
HEAT
OFF
START
B+B
B+B+S+M+G2
See Fig. 80 and Fig. 81 for wiring diagrams for
keyswitch No. 825129.
S
G1
G2
M
B
S
G1
G2
M
B
S
G1
G2
M
B
S
G1
G2
M
B
HEAT OFF ON START
B
S
G1
G2
M
Battery (2)
Solenoid
Glow Plug (Preheat)
Glow Plug (Cranking)
Accessory
Fig. 10 – Terminal Positions And Functions
Test switch terminals for continuity with keyswitch in positions shown.
B+B+G1
B+B
B+B+M B+B+S+M+G2
BBBB
Connector