Loader Bobcat 773. Manual - part 113

A

MC–02420

AHC/PWM CONTROLLER (Cont’d)
Description
Connector No. Pin No. Description

Voltage

Comments

C 430*

  A

Battery Power

12.0

  B

Ground

0

C 428*

  1

Power

12.0

  2

Model Input

12. 0

  3

Model Select–Input A

Not Used

  4

Model Select–Input B

Not Used

  5

Model Select–Input C

Not Used

  6

Open

0

C 429*

  A

Diagnostic Light

 4.0–11.0

Light ON–Light OFF

  B

Diagnostic Light

 4.0–11.0

Light ON–Light OFF

C 431*

  1

Attachment Control Signal

0 or 12.0

  2

Signal from Lift Control Input Handle

0.80–1.89–2.90

Low–Neutral–High

Signal from Lift Control Input Handle (Float)

3.8

  3

Return from Aux. Module Switch Input

9.5

  4

Signal from Tilt Control Input Handle

0.80–1.89–2.90

Low–Neutral–High

  5

Power to Tilt Spool Actuator

Not Used

  6

Signal from Lift Actuator Feedback Input

0.40–1.72–3.0

Low–Neutral–High

Signal from Lift Actuator Feedback Input (Float)

3.8

  7

Return from Aux. Detent Switch Input

12.0

  8

Power to Lift Spool Actuator

Not Used

  9

Signal from Tilt Actuator Feedback Input

0.40–1.72–3.0

Low–Neutral–High

10

Return from Aux. Rear Base Switch Input

11.0

11

BICS Status Input

0 or 12.0

Bar UP–Bar DOWN

12

Return from Aux. Rear Rod Switch Input

12.0

13

High Flow Solenoid Output

0 or 12.0

14

Diagnostic Input

No function

15

Low Reference to Resistive Inputs

Ground

16

Signal from Aux. Resistive Inputs

0.98–2.24–3.24

Low–Neutral–High

17

Lift Actuator Reverse Motor Output

0 to 12.0

18

Diverter Solenoid Output

12.0

19

BICS Aux. Lock Input

0 or 11.0

Bar UP–Bar DOWN

20

Auxiliary Relief Input

12.0

Key Left

21

Aux. Switch Module Detent Light

3.5 between 8.5 Light ON–Light OFF

22

Aux. Switch Module Momentary Light

3.5–8.5

Light ON–Light OFF

23

Lift Actuator Forward Motor Output

0 to 12.0

24

Aux. Spool Base End Output

0–6.0

Key Left (12 Volt)

25

High Reference to Resistive Inputs

4.3

 

±

 

0.1

26

Power to Aux. Switch Module

9.99–10.68

27

AHC Status Output

0 or 12.0

Bar UP–Bar DOWN

28

Switch Power

12.0

Key On

29

Tilt Actuator Reverse Motor Output

0 to 12.0

30

Aux. Spool Rod End Output

0–6.0

31

Tilt Actuator Forward Motor Output

0 to 12.0

*Schematic Connector Number

*

*

*

*

–10–16–

Service Manual

773 BICS Loader

Revised June 01

AHC/PWM CONTROLLER (Cont’d)

•

When the lights are flashing, the key needs to be
turned OFF and then ON. If the problem still exists they
will continue to flash.

•

Proportional flow cannot be engaged if the lights are
blinking.

•

Continuous flow (detent) can be engaged if alternate
blinking lights are OFF after the key switch is turned
OFF and then ON (during a proportional flow switch
failure).

Troubleshooting  Chart

The controller sends a diagnostic code to the Auxiliary
Hydraulic Switch lights when the conditions listed in the
chart below occur.

Conditions

•

Auxiliary  Hydraulic  Switch  lights  will  not  come  ON.
Check the following:

PWM fuse
Wires disconnected, shorted, or open.
Auxiliary hydraulic switch failure.
Module failure.

Use  the voltage tests in the wire identification
section to determine the cause.   (See    Page
10–16.)

Momentary LED

 (Item 1) [A]

Detent LED

(Item 2) [A]

PROBLEM AREA

PROBLEM CAUSE

Light Blinking

Light Off

Light Blinking

*Blinking/OFF

Light OFF

Light Blinking

Light Blinking

*OFF/Blinking

Base End Solenoid or Wiring

Rod End Solenoid or Wiring

Diverter Solenoid or Wiring

Proportional Flow Switch
      (Right Handle)

•

Wires Disconnected

•

Wires Shorted

•

Wires Open

•

Solenoid failed. Perform solenoid 
coil test.

•

PWM module failed.

•

Wires Disconnected

•

Wires Shorted

•

Wires Open

•

Solenoid failed. Perform solenoid 
coil test.

•

PWM module failed.

•

Wires Disconnected

•

Wires Shorted

•

Wires Open

•

Solenoid  failed. Perform solenoid 
coil test.

•

PWM module failed.

•

Wires Disconnected

•

Wires Shorted

•

Wires Open

•

Proportional flow switch failed. 
Check voltage to switch.
Perform handle test.

•

PWM module failed.

*Alternate Blinking Lights

A

P–03272

2

1

–10–17–

Service Manual

773 BICS Loader

Revised Nov. 01

AHC/PWM CONTROLLER (Cont’d)

Handle Testing

The right side steering lever handle switch (Item 1) [A]
controls the proportional flow to front auxiliary. Use a Ohm
meter to test the switch.

Disconnect the handle switch harness from the controls
harness (Item 1) [B]. Use the chart below to test the
handle switch.

Handle Switch Position

Test between

handle wires

Dk. Blue &

Dk. Blue/White

Dk. Blue/Yellow

& Dk. Blue/White

Dk. Blue/Yellow

& Dk. Blue

Full Left

4.5–5.5

K–Ohms

0.5–1.5

K–Ohms

3.5–4.5

K–Ohms

Center

4.5–5.5

K–Ohms

2.3–2.7

K–Ohms

2.3–2.7

K–Ohms

Full Right

4.5–5.5

K–Ohms

3.5–4.5

K–Ohms

0.5–1.5

K–Ohms

NOTE: Push the switch gradually from center to

either left or right. The Ohm reading must
change gradually. Replace the handle switch
assembly if required.

Solenoid Coil Testing

The front auxiliary solenoid coils (Item 1) [C] are located
in the hydraulic control valve. Test the solenoid coils with
a Ohm test meter.

Disconnect the coil from the controls harness. The correct
reading is 1–5 Ohms.

One K–Ohm is equal to 1000 Ohms.

1

B

N–17779

A

P–02129

1

–10–18–

Service Manual

773 BICS Loader

Revised June 01

C

N–17493

1

B

N–17783

1

A

N–17774

1

2

CONTROL HANDLE (ADVANCED HAND CONTROL)
(AHC)

Control Handle Unit Removal And Installation

To remove the handle control unit, slide the rubber handle
cover (Item 1) [A] up the handle.

Remove the two mounting bolts (Item 2) [A] from the
control cover.

Remove the control cover.

Disconnect the loader control harness (Item 1) [B] from
the handle control harness.

–10–19–

Service Manual

773 BICS Loader

Revised June 01