Keep it simple, the battery is definitely not OK, replace it with a proper one for the D4 then if still no joy work on the starter issue... IMO it's something there too cos as i said if the voltage doesnt drop below 10V while you crank it the starter should still spin just that it won't start
 
So update, I’ve ran a cable from the negative battery pole to the starter body and still nothing.

I’d attach the video of what you can hear but don’t think I can upload it.

For now I’ve removed the battery and will take it to the Battery suppliers to check if it’s good or bad
 
sierrafery said:
Keep it simple, the battery is definitely not OK, replace it with a proper one for the D4 then if still no joy work on the starter issue... IMO it's something there too cos as i said if the voltage doesnt drop below 10V while you crank it the starter should still spin just that it won't start
Click to expand...
What battery is correct for D4 ?
 
Checking better that Napa 019n battery of your's it became clear that it's not suitable for a D4 from the beginning cos it's a calcium battery with less CCA than required while calciums are weaker than AGMs at the same specs too while the charging systems for them are different as well :

quote from the WSM for D4: "The primary battery on petrol and diesel vehicles is a 90Ahr, 850A CCA AGM (absorbed glass mat) VRLA (valve regulated lead-acid) battery."
 
Last edited:
sierrafery said:
Checking better that Napa 019n battery of your's it became clear that it's not suitable for a D4 from the beginning cos it's a calcium battery with less CCA than required while calciums are weaker than AGMs at the same specs too while the charging systems for them are different as well :

quote from the WSM for D4: "The primary battery on petrol and diesel vehicles is a 90Ahr, 850A CCA AGM (absorbed glass mat) VRLA (valve regulated lead-acid) battery."
Click to expand...
Doesn’t make a difference that mine doesn’t have Stop/Start?
 
benh999 said:
Doesn’t make a difference that mine doesn’t have Stop/Start?
Click to expand...
Seems that it doesn't for those who wrote the workshop manual and as long as the charging system is the same stop/start or not an underrated calcium battery is deffinitely not good IMO
 
sierrafery said:
Seems that it doesn't for those who wrote the workshop manual and as long as the charging system is the same stop/start or not an underrated calcium battery is deffinitely not good IMO
Click to expand...
IMG_0119.jpeg

Something like this?
 
So the battery fits and to my suprise started the car, however the first crank sounded laboured as before. I took her out for a 5 mile drive and she was perfect. Got home, turned her off and then tried to restart her. Didn’t want to start. She did crank but it was really slow and the starter sounded horrid so I’m assuming I’ve got either a voltage drop to the starter motor or the starter motor is KO’d??
 
Update. Finally my mechanic managed to get out to look at the discovery. Turns out it’s the starter motor at fault. Starter is getting 12v and when I try to start her there’s no discernible drop on the voltage but she just won’t crank. New starter ordered from JGS 👍🏻
 
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