Regulator/Rectifier

Regulator/Rectifier - Introduction

Internally the rectifier/regulator consists of three diodes, one between each input and the positive terminal, and three Field Effect Transistors (FETs), one between each input and the ground terminal.

As the voltage of the AC signal from the alternator rises, the voltage controller switches the FETs to avoid over voltage on the output.

The diodes and FETs can be checked using a multimeter on DIODE setting. Disconnect the two electrical connectors from the rectifier/regulator and check the readings as indicated below.

note
This test does not check for voltage regulation.

Regulator/Rectifier - Fault

Fault

Possible cause

Action

Battery not charging

Main Fuse

Check the condition of the main 30A fuse:

Battery

Check the condition of the battery.

Refer to the instructions supplied with recommended battery charger to make sure the battery is serviceable.

Regulator/Rectifier

Disconnect the black and the grey connectors from the rectifier/regulator and proceed to pinpoint test 1:

Alternator

Test the alternator stator (see Alternator Stator).

Pinpoint Tests

Regulator/Rectifier - Pinpoint Test

Test

Result

Action

1

Check FET forward bias:

Positive (+) probe to rectifier black socket pin 1 to:

- Negative (-) probe to rectifier grey socket pin 1

- Negative (-) probe to rectifier grey socket pin 2

- Negative (-) probe to rectifier grey socket pin 3

0.4 V to 0.7 V

Proceed to test 2

Open circuit or short circuit

Replace the unit. Proceed to test 4

2

Check diodes function forward bias:

Negative (-) probe to rectifier black socket pin 3 to:

- Positive (+) probe to rectifier grey socket pin 1

- Positive (+) probe to rectifier grey socket pin 2

- Positive (+) probe to rectifier grey socket pin 3

0.1 V to 0.3 V

Proceed to test 3

Open circuit or short circuit

Replace the unit. Proceed to test 4

3

Check diodes reverse bias:

Negative (-) probe to rectifier black socket pin 1 to:

- Positive (+) probe to rectifier grey socket pin 1

- Positive (+) probe to rectifier grey socket pin 2

- Positive (+) probe to rectifier grey socket pin 3

Positive (+) probe to rectifier black socket pin 3 to:

- Negative (-) probe to rectifier grey socket pin 1

- Negative (-) probe to rectifier grey socket pin 2

- Negative (-) probe to rectifier grey socket pin 3

More than 1.4 V or OL on meter

Proceed to test 4

Less than 1.4 V or short circuit

Replace the unit. Proceed to test 4

4

Reconnect the harness and run the engine. Check the charging voltage at 2,000 rpm:

13 V - 15 V

Action complete - quit test

Fault still present

Test alternator stator (see Alternator Stator)

If alternator stator is serviceable, contact Triumph service

Circuit Diagram

Regulator rectifier circuit