D4 3.0 alternator change

[DiscoJeffster]

I’ve been working on cars now for 25 years and I can’t think of a task more frustrating than changing the alternator on a 3.0. I guess all the “it was a breeze” notes in other forums all relate to the 2.7 engine which I understand has more room, single versus twin turbo? Anyhow, getting the nut undone on the power output bolt was a nightmare. It wasn’t possible to move it more than an inch when connected, as the wire is bound to the starter motor. Getting into there to undo the nut was near impossible. The damn rubber cover that kept fooling my efforts. Lying on my ageing back, rather than a hoist, all conspired against me. Finish it off with the connector on the rear plug breaking and being stuck on and I uttered every swear work imaginable. I had to cut the wire and deal with the plug once out, then added some additional wire and soldered. All in all a bloody disastrous time!

It better last for the rest of the life of the car I can tell you, else I’ll just burn it rather than go through that again! Lol.

[letherm]

It better last for the rest of the life of the car I can tell you, else I’ll just burn it rather than go through that again! Lol.

I refer you to this thread.

Smoky D4 video

Martin

[DiscoJeffster]

[Graeme]

Doesn't the WSM say to unbolt the lead from the starter to allow the alternator to be pulled forwards enough to undo the nut?

Anyway, did you install a dedicated alternator cable with its own fuse?

[DiscoJeffster]

Doesn't the WSM say to unbolt the lead from the starter to allow the alternator to be pulled forwards enough to undo the nut?

Anyway, did you install a dedicated alternator cable with its own fuse?

No it does not. The workshop manual I have is quite bereft of words and shows mainly coloured pictures eluding to what to do. To remove the lead from the starter will require removing the starter as there is a bracket in the way of the stud. Frustratingly I had the starter out the previous day to do the turbo drain TSB but didn’t have time to do the alternator at the time, and hadn’t picked up on the alignment between the two jobs. I was ****ed to say the least.
And no, didn’t change the cable configuration.

[Milton477]

Thanks for the warnings. Won't try it in the bush then.
Well done for doing it yourself.

[DiscoJeffster]

Doesn't the WSM say to unbolt the lead from the starter to allow the alternator to be pulled forwards enough to undo the nut?

Anyway, did you install a dedicated alternator cable with its own fuse?

Graeme. Any idea on the ECU control wire? I believe it’s likely a PWM ECU feed to vary the output. I am also assuming that the loss of connectivity on this feed will send the alternator to 12V rather than max voltage? This is my concern as I had to repair that feed on my car and I worry of the repair was to fail, how would I be left? I presume with a useless alternator.

[drivesafe]

Hi JF, while I have not seen how the D3 alternator behaves when there is a communications wire failure, but on most vehicles, the alternator reg is preset to run at around 14.3-4v, not 12.0v.

In a number of makes, like Nissan’s, cutting the comms wire is the simplest was to do away with the ECU controlled Variable Voltage operation.

On a number of new vehicle makes, and I have not had time to experiment with this, but you now need to disconnect two wires going to the alternator, to cause it to go into the comms failure default voltage setting.

[Graeme]

The 3.0 alternator uses a LIN control line but that's the extent of my knowledge.

[Graeme]

No it does not. The workshop manual I have is quite bereft of words and shows mainly coloured pictures eluding to what to do. To remove the lead from the starter will require removing the starter as there is a bracket in the way of the stud.

Whilst I didn't remove the alternator, I removed the B+ cable from it and IIRC I was able to remove the cable from the starter without removing the starter by removing another bracket to gain access. My task was to fit a dedicated B+ cable so cutting the B+ cable at the starter was one of the jobs so perhaps my recollection of what I did isn't too accurate.