Introduction

Introduction

Over recent years many different styles, shapes and colours of wiring connectors have been utilised on Rover vehicles as ever increasing reliability and integrity is sought. Probing each of the different types of connector with test equipment requires differing techniques. The following steps must always be remembered when tackling electrical fault diagnosis and repair.

1. Verify the complaint

Turn on all the components in the problem circuit to verify and check the accuracy of the customer complaint.

Note the symptoms. Do not begin disassembly or testing until you have narrowed down the problem area.

2. Analyse the wiring diagram

Look up the wiring diagram in this Repair Manual for the problem circuit. Determine how the circuit is supposed to work by tracing the current paths from the power source through the circuit components to earth. Also trace circuits that share wiring with the problem circuit. The names of the circuits that share the same fuse or earth are shown in the Power and Earth Distribution section. Try to operate any shared circuits you didn't check in step 1. If shared circuits work OK, the cause must be in the wiring used only by the problem circuit.

If several circuits fail at the same time, the fuse or earth path is a likely cause. Based on the symptoms and your understanding of the circuits operation, identify one or more possible causes of the problem.

3. Isolate the problem by testing the circuit

Make circuit tests to check the diagnosis you made in step 2. Keep in mind that a logical, simple procedure is the key to efficient fault finding. Test for the most likely cause first.

Try to make tests at points that are easily accessible.

4. Fix the problem

Once the specific problem is identified make the repair. Be sure to use the proper tools and safe procedures.

5. Intermittent failure

The term 'Intermittent Failure' is used when a system may have had a failure but checks out OK through all your tests. You may need to road test the vehicle to reproduce the failure, or if the problem was a loose connection you may have unknowingly solved it while doing tests.

6. Open or short circuits

An 'Open' is a break in a wire or at a connection. A 'Short' is an accidental connection of a wire to earth, or a positive feed.

In simple electronics; this means something won't work at all.

In complex electronics; like Electronic Control Units (ECU's) this means something works but not the way it is supposed to.

7. Confirm and verify repairs

Always confirm that your diagnosis and repair is complete by verifying the complaint and symptom. Then road test the vehicle when repairs are completed.