AM2 Fault Finding

Hello, I’m taking my AM2 resit on Thursday and I’m going back to do fault finding. My main issue is identifying where the fault lies between when using the continuity/voltage tester. Can anybody who has recently sat through this exam give me some advice on simple tactics and an approach of identifying thoroughly a fault and it’s location. Sorry if this question is a little vague, it reflects my thinking in the current exam climate haha. Thank you in advance to those I may not get back to.

Welcome to the forum.

For the AM2 fault finding you will encounter short circuits, open circuits, reversed polarity, high resistance and incorrect cables in terminals.

For a short circuit:

Measuring resistance between conductors where you expect to find open circuit and getting a low value of resistance.

Measuring between the conductors at different points in the circuit narrow down the point of fault.

Similarly but reversed with open circuits.

Where there is reversed polarity this would often be an observational exercise to determine where the conductors have been swapped over, but generally measuring continuity from the start along the length of one conductor at the accessible points until the reading changes from low resistance to open circuit would be the point of crossed cables.

High resistance or low insulation resistance would be addressed in a similar manner to a  short or open circuit measuring at different points to find the change in resistance.

Incorrect cables in terminals is an observational thing, to check what should be where.

A diagram showing a couple of options: