Can anyone help with any information that will help me decide if my Alternator is not charging, or my battery is duff. I have a 94 Renault Espace diesel that is causing problems on the cold dark mornings, i.e..e often not enough charge to turn over enough to start. Last winter I had an alternator fault and had the alternator repaired at a local alternator & starter repair shop. I still had problems so decided I bought a new battery. spring/summer/autumn, driving without much electrical load so had no problems. This winter come dark nights, short drives and cold mornings and the starting problem is back. I tested the battery and alternator as per the Haynes manual (yes I have doubts as to whether I can believe this book). Battery volts cold were ok, about 12.7v. With engine running the battery volts were about 14.v with no load, so far all as per "the book". With full electrical load on, the battery volts dropped to about 12.3v. Haynes says the alternator should hold the output to between about 13.5 and
14.4v. I went back to the alternator repair place, and he said the alternator was doing what it should, and I needed a new battery. Who is right? The Haynes manual or the repair man? I obviously don't want to pay for a new battery if it is the Alternator, and vice versa.Any help or helpful links appreciated
Thanks
John