Check the Negative (-) terminal clamp is tight
Check the Positive (+) terminal clamp is tight. CAUTION If using a spanner to tighten terminal, be careful not to short it on the bodywork
Check battery is generally secure. If loose, tighten the battery retainer
To tighten, a 10mm socket is needed. Not too tight because you may damage the battery casing
Ensure you apply equal tension to the other side of the battery retainer
Find a Haynes product for your Subaru:
Search by registration mark
Search by make & model