- Dec 9, 2008
- Reaction score
- Woking, UK
- Your Mercedes
- '71 350 SL, Mercedes 350 CLS SB, '94 Shogun 2.8 LWB, '73 Porsche 914
Hi - I've been having flat battery issues on my '72 450 SL. I have fitted a new battery and with the engine off it shows 12.7 Volts. With the engine running I have 13 Volts at the battery and the alternator. I swapped out the alternator and the regulator for replacement (not new - off the breaking wreck I have) but still the same. Someone told me that this is fine for this car due to the sensitive D-Jetronic injection system, but I have read elsewhere that a battery needs between 14.3 and 14.8 Volts to charge properly. Any ideas please? Incidently, the rev counter has started bouncing around the place and the indicaters have stopped indicating, but these could be unrelated!