TE20 Generator and Alternator wiring diagrams

F D
TEA 20 WIRING DIAGRAM - ORIGINALLY POSITIVE EARTH
AMMETER
GENERATOR
GENERATOR WARNING LAMP
D
E
A
F
GENERATOR
CONTROL BOX
(REGULATOR)
Spark Plugs firing order
1-3-4-2
#1 cylinder is at the front
1 2 3 4
DISTRIBUTER
-
+
LIGHT
SWITCH
Fuse
15A
IGNITION SWITCH
- +
STARTER
STARTER
SOLENOID
- BATTERY +
HEAD LIGHTS
COIL
Positive Earth
TAIL LIGHTS
To polarizer the Generator to suite the polarity, remove the F & D leads from the Generator and with a lead connected to the Negative
terminal of the battery, flash the Field “F” terminal on the generator til you see a small spark, then replace the leads in the same position.
NOTE! The Generator must be attached to the chassis and Battery connected to maintain the polarity.
Any break in the system will require the process to be repeated.

TEA 20 WIRING DIAGRAM - for TRACTORS CONVERTED TO NEGATIVE EARTH
F D
GENERATOR
GENERATOR WARNING LAMP
D
E
A
F
GENERATOR
CONTROL BOX
(REGULATOR)
Spark Plugs firing order
1-3-4-2
#1 cylinder is at the front
1 2 3 4
AMMETER
DISTRIBUTER
+ -
LIGHT
SWITCH
Fuse
15A
IGNITION SWITCH
- +
STARTER
STARTER
SOLENOID
BATTERY
+ -
HEAD LIGHTS
COIL
Negative Earth
TAIL LIGHTS
To polarizer the Generator to suite the polarity, remove the F & D leads from the Generator and with a lead connected to the Positive
terminal of the battery, flash the Field “F” terminal on the generator til you see a small spark, then replace the leads in the same position.
NOTE! The Generator must be attached to the chassis and Battery connected to maintain the polarity.
Any break in the system will require the process to be repeated.

When and How to Polarize a Generator
Polarization is a procedure which matches the polarity for the generator and the voltage regulator by permitting a surge of current to flow
through the generator, correctly polarizing it. Damage to electrical components can occur if polarities do not match.
Ferguson tractors have utilized both positive and negative ground systems.
Delco 6V systems have positive ( + ) ground.
Delco 12 V systems have negative ( - ) ground.
Lucas systems for both 6V and 12V models have positive ( + ) ground.
Lucas systems converted to electronic distributer with a 12V system have negative ( - ) ground.
Polarization of the generator should take place whenever any of the following events occur:
1. The battery is replaced or disconnected from the tractor
2. The generator is replaced or serviced
3. The regulator is replaced or serviced
If any of these events occurred, do not start the engine until polarization is done.
The polarity of the generator must be set to match that of the voltage regulator.
For positive ground systems: To polarizer the Generator to suite the polarity, remove the F & D leads from the Generator and with a
lead connected to the Negative terminal of the battery, flash the Field “F” terminal on the generator til you see a small blue spark, then
replace the leads in the same position as they were before.
For negative ground systems: To polarizer the Generator to suite the polarity, remove the F & D leads from the Generator and with a
lead connected to the Positive terminal of the battery, flash the Field “F” terminal on the generator til you see a small blue spark, then
replace the leads in the same position as they were before.
NOTE! The Generator and Battery Earth must be attached to the chassis to maintain the polarity.
Any break in the system (i.e. battery or generator removed or regulator wiring disconnected) will require the process
to be repeated.

Ind Bat
TEA 20 WIRING DIAGRAM - NEGATIVE EARTH
ALTERNATOR
ALTERNATOR WARNING LAMP
Spark Plugs firing order
1-3-4-2
#1 cylinder is at the front
1 2 3 4
GENERATOR
CONTROL BOX
(REGULATOR)
REGULATOR
NOT
REQUIRED
AMMETER
DISTRIBUTER
+ -
LIGHT
SWITCH
Fuse
15A
IGNITION SWITCH
- +
STARTER
STARTER
SOLENOID
BATTERY
+ -
HEAD LIGHTS
COIL
Negative Earth
TAIL LIGHTS
The Alternator requires no Polarization process

D
F
Ferguson TEA20 Tractor with a Generator
12V Positive earth system plus Ammeter wiring explained
Yellow
May also be grounded
at starter switch
Green
Note! If no Ammeter,
wire directly from
A on Regulator to
the starter switch
as shown
Yellow
Green Strip
-
Black
Ammeter
D
E
A
F
GENERATOR
CONTROL BOX
(REGULATOR)
Yellow
White
Yellow
Green Strip
Charge Indicator
White
Keyed Ignition Switch
ON/OFF
Fuse 15A
Circuit for accessories
if required
Ground return from
accessories, if required.
Terminate on the “-” battery
terminal or any where on
the chassis i.e. the ground
bolt on the starter switch
1 2
+
3 4
DISTRIBUTOR
Firing seq. 1-3-4-2
(Cilinder #1 at front of moter
Red
Black
+ -
LUCAS
COIL
12V
STARTER MOTOR
LUCAS 25079J
Yellow
Green Strip
-
+
12V
Battery
Firing order 1-3-4-2 #1 cylinder is at the front
Negative Earth
Can be grounded to the chassis at
the Oil Filler Casting or the mounting
bolts on the starter motor or one of
the steering housing bolts.
Anywhere will do so long as there is
a good earth connection.
To polarizer the Generator to suite the polarity, remove the F & D leads from the Generator and with a lead connected to the Negative
terminal of the battery, flash the Field “F” terminal on the generator til you see a small spark, then replace the leads in the same position as before.
NOTE! The Generator must be attached to the chassis and Battery connected to maintain the polarity.
Any break in the system will require the process to be repeated.

Ferguson TEA20 Tractor with a Generator
12V Negative earth system
Yellow
D
F
Yellow
May also be grounded
at starter switch
Green
Note! If no Ammeter,
wire directly from
A on Regulator to
the starter switch
as shown
Yellow
Green Strip
+
Black
Ammeter
D
E
A
F
GENERATOR
CONTROL BOX
(REGULATOR)
White
Yellow
Green Strip
Charge Indicator
White
Keyed Ignition Switch
ON/OFF
Fuse 15A
Circuit for accessories
if required
Ground return from
accessories, if required.
Terminate on the “-” battery
terminal or any where on
the chassis i.e. the ground
bolt on the starter switch
1 2
-
3 4
DISTRIBUTOR
Firing seq. 1-3-4-2
(Cilinder #1 at front of moter
Red
Black
-
+
LUCAS
COIL
12V
STARTER MOTOR
LUCAS 25079J
Yellow
Green Strip
+
-
12V
Battery
Firing order 1-3-4-2 #1 cylinder is at the front
Negative Earth
Can be grounded to the chassis at
the Oil Filler Casting or the mounting
bolts on the starter motor or one of
the steering housing bolts.
Anywhere will do so long as there is
a good earth connection.
To polarizer the Generator to suite the polarity, remove the F & D leads from the Generator and with a lead connected to the Positive
terminal of the battery, flash the Field “F” terminal on the generator til you see a small spark, then replace the leads in the same position as before.
NOTE! The Generator must be attached to the chassis and Battery connected to maintain the polarity.
Any break in the system will require the process to be repeated.

This is the colour coding of the harness that I purchased
all going well, this maybe a standard colour coding used in Australia.
NOTE! The harness did not have the wires in the appropriate place for the ammeter, hence the comment at the Ammeter**
Generator
Charge light
Regulator
Ignition Switch
Coil
Ammeter
Distributer
“F” small lug green to “F” on regulator
“D” large lug yellow to “D” to charge light then extended to “D” on regulator
white to ignition switch
yellow from “D” on generator then extended to “D” on regulator
“F” green from generator
“A” yellow with green stripe to positive side of starter switch
“E” black to earth
“D” yellow from generator via charge light
white from charge light then to + on coil for negative earth or - on coil for positive earth
yellow with green stripe to positive side of starter switch
white to ignition switch
cut the yellow with a green stripe wire in an appropriate place, connect the end of the cut wire from the
regulator to the + side of the ammeter and the other end to the - side of the ammeter (i.e. “A” on regulator
to “+” on ammeter then “-” on ammeter to battery side of starter switch
Note!** you will need to add wire to extend to the ammeter
some distributers have 2 wires 1 red and 1 black.
connect the black to “-” on coil and red to “+” on coil.
Alternator
Regulator
Charge light
Alternator conversion kit B8810 from Bare-Co
Note! Tractor must be Converted to Negative earth system
disconnect (cut back & tape up) all wires from the generator..........................
}
disconnect (cut back & tape up) all wires from the regulator........................... these wires are now NOT required
disconnect (cut back & tape up) original yellow wire(s) on the charge light.
New Harness connect red wire with large spade terminal to “B+ on alternator, other end to battery “+” or if fitted, ammeter “+”
((another red wire is then required (not supplied) to run from ammeter - to battery +))
connect new yellow wire with small spade terminal to “D+” on alternator and terminate on charge light in place of
the original yellow wire(s) Job Done.
Disclaimer: While I have done my best to ensure acsuracy on these eight pages, no responsibility is accepted for errors or omissions of information

Ferguson TEA20 Tractor with an Alternator
12V Negative earth system
1 2
3 4
Alternator
DISTRIBUTOR
Firing seq. 1-3-4-2
(Cilinder #1 at front of moter
Bat
New Yellow as provided in Alternator Harness
D+
Red
Black
-
+
LUCAS
COIL
12V
Red
+
Note! If no Ammeter,
wire directly from Ammeter
“B” on Alternator to
the Positive Battery
Terminal. Otherwise
add a new wire (red)
from the - on the ammeter to
the Positive Battery Terminal
STARTER MOTOR
LUCAS 25079J
D
E
A
F
Red continued
GENERATOR
CONTROL BOX
(REGULATOR)
No Ammeter
see note 1
White
Yellow
Green Stripe
+
-
Charge Indicator
White
12V
Battery
Fuse 15A
Circuit for accessories
if required
Ground return from
accessories, if required.
Terminate on the “-” battery
terminal or any where on
the chassis i.e. the ground
bolt on the starter switch
Keyed Ignition Switch
ON/OFF
Negative Earth
(Some tractors have the
Battery Grounded to the
chassis at the Oil Filler Casting
some to one of the mounting
bolts on the starter motor )
The Alternator requies no Polarization process.
Note 1: this wire can also be terminated at the battery “+” terminal
instead of the battery side of the starter switch