Thread: What happened to your D3/D4 today?

Originally Posted by John_D4

Weirdly, after a few days of the car not charging over 12.7v following a battery change and a battery reset, I got in it this morning and it’s charging 14.5v. Maybe it just needed a couple of days rest to get its thoughts right

Mine did this when I was paying attention to the voltage at one point. Put it down to the car testing it's new battery by running it down, and seeing charge rates (or some similar process). All part of the programming it seems?

Fitted a second hand Safari snorkel purchased from Nomadic/ Brian.

I ordered the templates from ARB, they were shocked when they arrived!
They were all very second hand! Their last set.

I'm getting a friend to scan them and draw them up in CAD for others to download and print out.

Originally Posted by veebs

Mine did this when I was paying attention to the voltage at one point. Put it down to the car testing it's new battery by running it down, and seeing charge rates (or some similar process). All part of the programming it seems?

It’s kinda weird. It was charging mid 12’s, then suddenly 14’s, last couple of days mid to high 12’s with occasional 13.5/13.7 then back to mid to high 12’s.

New battery is charging better and doesn’t need as much voltage fed into it??

Originally Posted by John_D4

It’s kinda weird. It was charging mid 12’s, then suddenly 14’s, last couple of days mid to high 12’s with occasional 13.5/13.7 then back to mid to high 12’s.

New battery is charging better and doesn’t need as much voltage fed into it??

With the D4, if your cranking battery is in good condition and anywhere between 80% and fully charged, it is not unusual to see operating voltages in the mid 12v area.

But when ever you are driving and take your foot off the accelerator, the voltage can jump to as high as 14.7v while your foot is off the accelerator.

The instant you press the accelerator again, if the cranking battery is 80% charged or higher, the voltage will drop to the mid 12v area again.

If your battery is less than 80% charged or in pour condition, the alternator will run at a constant high voltage, up to 14.7v, regardless of whether the accelerator is pressed or not.


Furthermore, fitting a new battery does not mean it is in a fully charged state, as there is no way of knowing how long the battery sat at the battery sellers for.

Oh right, so correct me if I’m wrong, but the reason that I used to constantly get charging above 14.5v was probs because the battery was on the way out. Now I have a new battery and it was charged on the home battery charger until full, the car doesn’t need to charge flat out.

So, then theoretically, if I let the car sit for a week or so until the battery has gone down a bit and then start it, it will probs charge in the 14’s again as the battery is flatter then relax a bit once charged again.

Hence the term "smart alternator" reactive to the battery condition and system loads. Thanks for the plain English explanation Tim.

I knew it was a smart alternator, but I didn’t know all that. Thanks again Tim

Dropped my compressor guard and the cover to give it a cleanout as I’ve been through a bit of mud and water lately.

Definitely needed it!