Symptoms of alternator failure??

[Hainsie]

So what are the symptoms of alternator failure??

[Tipper]

Is this a QI question?

Will the lights flash and the klaxons sound if I say...flat battery?











Sorry, couldn't help myself.

[Keith Williams]

If you are driving the car at the time, the warning lights on the car will illuminate in turn and shortly after the car will die. You will be able to jump start the car but it will not keep running without a fully charged battery or one that is been charged by the alternator.

[Hainsie]

True, battery not charging is a clue, but I thought it better to turn the question around, rather than say what symptoms there are to see if they match!

[Bandit]

The theory is that the red LED with the battery symbol is a reliable indicator of whether the battery is charging, but sadly not... If the alternator output has dropped to a tiny fraction of what it should be producing, the LED may not illuminate. If the current out of the alternator has stopped being DC and become AC, the LED may not illuminate. About the only scenario where it can be absolutely guaranteed to illuminate is when the alternator drive belt snaps or the alternator seizes/stops being driven.

A primitive but very effective test of what your alternator is putting out is to disconnect the battery leads while the engine is running. If the engine keeps running happily, the alternator is doing its job.

[Rob Bell]

What are the car's symptoms? Loss of charge while driving, or failure to maintain charge overnight?

The other test to do is to measure the voltage over the battery with the engine running. It should be healthily over 13v. If around 12v then there could be a charging problem, and if under 12 then there is a significant problem.

[Chris Tideswell]

This may be only applicable to late MEMs3 F’s and TF’s, when the ignition is turned on but without the engine running the warning lights on the dashboard should illuminate as check including the battery warning light, if the latter doesn’t illuminate then the alternator is faulty.

As said the best way is using a meter to check the voltage with the engine running as the alternator could well be delivering a higher voltage then 14V not just a low or no volts.

[Malcbox]

.....the alternator could well be delivering a higher voltage than 14V not just a low or no volts.

If an alternator failed in this way, what might be the effect on the car battery? I was supposing that a battery will only hold the charge that it is designed for, but I am far from an expert in these matters.

[Hainsie]

Thanks Chaps.

Symptoms are: lots of flashing dash lights, power steering failure, miss fire. AA man got it going and my friends got home. Battery is only 30% charged and only showing 12v when alternator is "running". Dodgy whine from it too.

Have ordered him a new alternator today.

[Rob Bell]

Certainly sounds suspect. Make sure you order the Magneti Marelli and not the Bosch alternator; the latter has connections suited to the later wiring loom, so won't be a direct fit to your early F.

[Chris Tideswell]

.....the alternator could well be delivering a higher voltage than 14V not just a low or no volts.

If an alternator failed in this way, what might be the effect on the car battery? I was supposing that a battery will only hold the charge that it is designed for, but I am far from an expert in these matters.

If the voltage is too high it can damage the battery, too low and the battery will not be charged up.

[colintf]

Thanks Chaps.

Symptoms are: lots of flashing dash lights, power steering failure, miss fire. AA man got it going and my friends got home. Battery is only 30% charged and only showing 12v when alternator is "running". Dodgy whine from it too.

Have ordered him a new alternator today.

hope that sorts it Steve

[Hainsie]

Advice from MGOC spares and Rimmers say its YLE102430, which I've ordered, for a 1998 VVC air conditioned model. No idea if its bosch or Magnetti as it didn't say, but a genuine Rover part.

[Chris Tideswell]

Advice from MGOC spares and Rimmers say its YLE102430, which I've ordered, for a 1998 VVC air conditioned model. No idea if its bosch or Magnetti as it didn't say, but a genuine Rover part.

Interesting YLE102430 (Bosh) is the part number for the later alternators 2001 on with the full MEMs3 ECU, the connections are quite different to the earlier F's with Magnetti. Although you have to assume Rimmers have got it right with cars fitted with aircon.

I got my new alternator from a local motor factors so I could compare the old and new there-and-then.

The good news is that changing the alternator on aircon F should be a lot easier then on non-aircon F due to it's location.

[Rob Bell]

Exactly why I mentioned it Chris:



The alternator on the left of the picture is the Bosch item, the one on the right the Magneti. The Magneti has three stud connectors, whereas the Bosch has a Lucar-type connector. However, Rimmers are usually pretty good: if they've sent you the wrong one, I am sure they'll exchange it for the correct one FOC.

[colintf]

trouble is, Rimmer's part numbers aren't totally infallable.

I've re-educated them about a 260 part before now, after they sent me the wrong part (which was the right one according to their parts list, but in reality, wasn't)!!

[Geoff.F]

trouble is, Rimmer's part numbers aren't totally infallable.

But they do have a "No Quibble Put It Right" policy which you do not get on E-Bay.
Geoff F.

[Rob Bell]

Looking at Rimmers website, the part number they quote for the Mareli Magneti alternator is YLE101530E

Have you got your alternator from Rimmers yet Hainse?

[Hainsie]

Nope, as I took all advice as expert, I have the wrong one!!

It will be exchanged.