ML W164 charging problem

[Hercules]

Hello there, I have lately investigating a problem Having engine starting from cold, engine starts OK but no as quick is used to do before , it takes about 2 to 3 sec to start compare to 1 sec as usual
At first I thought it was the battery and I replaced it last March,I went to the battery vendor yesterday to check the battery and it confirmed that the battery is OK it just back need recharging.

I checked the battery when I got home and the voltage was 12.8 volts engine of and 13.8 engine running at 2500 revs.
I did some research and if i understood right the voltage out of the alternator should be around 14.4 volts.

Is the regulator need to be replaced or is OK ??

 

[Blobcat]

If the engine is turning over fine but not starting it’s not a battery or charging issue.

If the engine is sluggish at turning over then you have a battery issue.

 

[kid-jensen]

Follow the heavy cable from the starter motor and clean/re-make any connections where there's a join. They could be partially corroded, thanks to our generous MOT splashing so much salt around...

When you're passing hundreds of amps, it only needs a few milliohms to loose enough volts to affect the starting, so make sure there's good clean electrical path to the battery. It's a long cable, which only makes things worse.

That being said, slower starting must be expected when the temperature is as low as it's been lately