TDV8 Sport alternator query , one for the gurus I think.

[Nomad9]

Hi There,
2007 TDV8, 161,000 klms on the clock, I have already posted about this issue before, however the vehicle was delivered back this afternoon by the RAC and I now have a few more queries. I sort of know the final outcome however I would just like a bit of verification.

The guy in Denham fitted a battery to get some basic functionality back, door locks, handbrake and gear selection, not the right battery. However when the battery was installed the RR started, this allowed the vehicle to me moved with the camper trailer etc and put on the trailer.

This afternoon getting the vehicle off the transporter with the undersized battery fitted vehicle wouldn't start so I fitted the new correct battery. RR started and ran perfectly, even the battery light went off. At this point I started to think that maybe this was just a battery fault and maybe not the alternator........ don't I wish.

Ran the camper trailer up to the shed, unhitched the camper and put the RR in the shed. Battery light still off, everything working fine, no dash lights on etc. Thought I would check the battery terminal voltage, 13.58 volts, steady. However and this is a bit of a biggie, there was a bit of an electrical smell. Might just be my paranoia........ but I was sure I could smell something electrical.:(

Turned the engine off and connected the CTek charger, the battery was it appeared a 1/2 to 2/3 discharged according to the charger, the battery voltage at the terminals with the charger attached was 12.91 volts and climbing as I suspect the charger was kicking in.

I'm committed to changing the alternator I believe this is definitely at fault, I would just like to try and understand the failure mechanism. Would it be possible for the alternator to be "rooted" and yet still keep the alternator or at least the battery light extinguished until the battery drew its last breath? I'm also trying to determine if I originally had a battery fault or an alternator fault which then totally "Ronnied" the battery, the battery was a Century 850 CCA about 18 months old.

When the problem originally happened the battery light came on and stayed on until 23 to 25 klms later when the vehicle just stopped with the majority of the dash lights on. After that there wasn't enough power to turn the interior lights on, the battery voltage read 0 volts. :confused:

Since fitting the new battery the battery light on the dash extinguishes immediately after the engine starts.

Any constructive enlightenment is welcomed.

Cheers Marty.

[Graeme]

The battery could have a broken internal connection causing intermittent low voltage. However these alternators fail because the Zener/avalanche diodes deteriorate with usage whereby their trigger voltage that shuts-down (short circuits) excessive voltage to protect the vehicle's electronics gradually drops from the original 30V to normal charging voltage. Hence a low charging voltage doesn't trigger the reverse current flow but when the voltage rises just a little more, the diode that has deteriorated the most short-circuits.

On a different tact, there is a noise suppression capacitor attached to the outside of the gearbox that is known to fail short-circuit thereby drawing excessive current.

Edit: The reverse-trigger voltage of the diodes is affected by heat, thereby altering the voltage at which the short-circuit occurs and possibly causing more than just a single diode to short-circuit.

A single short-circuiting diode (only 1 phase affected) may be overpowered by the other 2 phases still functioning properly allowing voltage to be maintained with the engine running but the battery will soon be drained by the short-circuiting diode once the engine is stopped.

[Nomad9]

Hi Graeme,
The noise suppression capacitor attached to the outside of the gearbox, are you possibly suggesting that this might have failed (as well)? Is this a common failure mode, what does this look like and where abouts on the gearbox is this gizmo, how do I know if it has failed or not? Does it get warm / hot?

Do I simply replace the alternator and battery and then see if everything is OK? Does this attachment on the gearbox have a fault code?

Thanks for the assistance, appreciated.

Cheers Marty

[Graeme]

The gearbox capacitor can be disconnected and tested for short circuit and something to be checked if a check of the alternator current draw as suggested below doesn't implicate the alternator. However the symptoms described are most typical of failing alternator diodes. That the temporary battery was flat when about to unload really indicates that the original battery is not the cause and therefore most unlikely to have an internal break, so something is drawing lots of current.

I would disconnect the starter cable from the battery (I suspect that the alternator connects to the starter but only guessing), put some charge into the battery then remotely test reconnect the starter cable, first fitting a jumper lead to the battery then to the cable to keep possible sparks away from the battery. If sparks occur then the starter/alternator are drawing current yet they should not and therefore basically proved that the alternator has at least 1 short-circuiting diode. You would have to disconnect the starter cable at the fusible link to leave the rest of the vehicle powered to know that current is indeed being drawn on the starter/alternator cable.

[Nomad9]

Hi Graeme,
I have started replacing the alternator so I have various bits disconnected now, I'm committed to fitting a new alternator, this seems to be the most likely bit that is broken according to others comments. I have the alternator and I have the new battery so I'll soldier on.

Where abouts is the gearbox bit you talk about? Is it easily removable or do I need the anatomical features of a new-born to reach it?

Cheers Marty

[sheerluck]

Marty, it's on the right hand (driver's side) of the transmission, and looks like this:
http://www.aulro.com/afvb/attachment.php?attachmentid=111828&stc=1&d=1469499341

Very easy to see and get to once the transmission shield is removed.

[Nomad9]

Hi Dave,
Thank you, I'll have a look when I get the RR up on the hoist. My wifes birthday today so I'm not sure now is the right time to be grovelling under Rex, time and a place, thanks for the photos, makes things much easier. Are these a common failing point? Would you happen to have a part number?

Cheers Marty

[sheerluck]

I wouldn't say common. The one on my D3 died, and judging by the posts on Disco3, it happens occasionally. At least they are inexpensive and easy to replace.

[Nomad9]

Hi Dave,
How did the failure show itself? Also do you have a part number you could throw my way...... please?

[sheerluck]

Hi Dave,
How did the failure show itself? Also do you have a part number you could throw my way...... please?

Mine was easy to diagnose, it had fallen apart. :D

Part number is NNW502820 or LR020488

[Nomad9]

Hi Graeme / Dave,
Am I missing something here? I have read several nightmare reports on getting access to the alternator, however I have started today, removed the small guard at the front and the inner guard plastic protector, and there it is the alternator, see attached pictures. I haven't removed the belt yet I thought I would have a look at the underside first.

In comparison to some of the other jobs I've done this looks deceptively easy, is mine different to others. I was going to remove the really large earth strap to the left to gain better access.

I'll progress more at the weekend..........

Cheers Marty.

[Graeme]

Your vehicle doesn't appear to have a pipe running across the top of the alternator then dropping down the back (as shown in the WSM diagram) in front of a bolt that has to be removed. My brother's MY08 has dynamic stabilizer bars so perhaps the pipe is for that feature. Step 12 in the WSM procedure refers to a nut that has to be removed, which my brother thought would not make any difference but once removed, the pipe over the top could be sprung out of the way.

[Nomad9]

Hi Dave,
For $45 from Rimmer bros for a LR genuine part including postage and delivery I'm getting a new one. Might as well, if the other one is OK I'll keep it as a spare.

Thanks for the info.

Cheers Marty

[Nomad9]

Hi There,
Unfortunately business sometimes gets in the way of pleasures such as replacing the alternator on "Rex the Sport".

OK following the instructions supplied by all things appear to be going well, no blood drawn yet......

Whilst I have gone this far I thought I would also replace the inner serpentine belt seeing this is the one the dealer sold me, I thought there was only one belt...

Got the outer belt off, no problem at all, the inner belt doesn't appear to be as easy. I have the Rave manual which is 5500 pages and I can't find the right section, this is easier.......

Which pulley releases the inner belt? I have located what I believe to be the nut / bolt that has something to do with the release of the tension however is extremely tight, before I get to strong and break something is this the right bolt to be undoing? Which direction do I turn it? I have assumed to the right to lift the L/H pulley, see picture attached.

As usual any assistance provided greatly appreciated.
Cheers Marty

[Nomad9]

Hi There,
It's ok figured it out.......... Had to go to "plan B", the tensioner was extremely tight because it had seized in position. Cut belt off, now looking to either fix the tensioner or replace. Have strategically applied some WD40 to the now removed tensioner, after about 15 minutes some movement is now evident, ever hopeful...........

Oh and the serpentine belt supplied was also the wrong one, I'm off to Land Rover to get a replacement. Good job I didn't have that one as a spare........

And it is the lower pulley to the left (in the 1st picture), not the top pulley as I first thought.

Cheers Marty

[Nomad9]

Hi There,
OK, alternator is off the engine and on the bench. Bit tight and requires a bit of juggling. Tried to lift the bottom out first initially, nearly made it but not quite. Pushed alternator back in again and manipulated the top out first, with a bit of turning and jiggling around finally came out.

The top bolt is tight to squeeze past the bottom hose however it came out fairly easily. The front bolt at the bottom is a plick, this was verging on the hardest bit. Very difficult to squeeze out between the turbo pipe and the coolant pipe, see first picture. I couldn't actually get that bolt out until the alternator was pivoting on the top bolt. My advice would be to leave the top bolt in until everything else has been removed.

What JC said about the 1/4 inch drive socket set is spot on, also get a six point socket and not a multi point, these bolts are quite "soft".

The hydraulic line you can see in the last picture, I cable tied that down out of the way until the alternator was out, then released it again. The live terminal plug and rubber boot is a PITA. I smeared some o-ring grease over the boot so it tended to slip into the right place rather than need pushing.

I'm going to remove the rear air into the turbo pipe to give it a clean, remembering to put it back before the alternator goes back.....

End of the removal stage.

Cheers Marty.

[Nomad9]

Hi There,
New alternator fitted now on the home stretch. Fitting the alternator on your own can be a challenge especially the lower back bolt. The both has to be in place before the top bolt is located. Every time the alternator was lifted into place the bolt fell out of the hole, of course it did, why didn't that happen when I was taking it out?

My way around that was to install a small o-ring around the bolt and then push the o-ring and the bolt into the hole, the o-ring holds the bolt in place whilst the top bolt is inserted and nipped up.

In another 160k when the alternator is replaced possibly someone will wonder why there is an o-ring around that particular bolt.......

Just waiting for the new belts to arrive, they weren't in stock, of course they weren't...........:)

Job done.

Cheers Marty.

[Nomad9]

Hi Dave,
My new part arrived today, I was expecting something a bit larger, the picture you posted makes the part look deceptively large. All good, as soon as I've fitted the belts I'll go looking for this part. Thanks again.
Cheers Marty

[Nomad9]

Hi Sheerluck,
Replaced, mine looked OK and my multimeter told me the old one was the same as the new one, replaced anyway. Getting that gear linkage in place again was a bit of a challenge......... Thanks again for the heads up.

Cheers Marty

[Nomad9]

Hi There,
Whilst fitting the fan I just happened to notice that one of the blades was cracked, noticing this was just "sheerluck" (scuse the pun), this could have been a bit messy.:o:o Ordered one from TRS waiting for it to arrive, can finish off then.

Cheers Marty