9 replies to this topic

[Brigbeale]

As title suggests, I need to replace the alternator on my Son's 1990 998 Racing Green.
As far as I am aware, the fitted alternator is original.
He had charging problems a couple of years ago and I had the alternator repaired at a local auto electrician who replaced the regulator pack for around £45.
Charge-wise, it has been fine until about a month ago, when I had to jump start him to get to work. The car would turn over quite happily but wouldn't start. With the jump leads connected it started straight away.
As he works at Halfords, he ran a check on his system which showed the battery was flat and the charging system was 'satisfactory'.
When he returned home, I put the battery on charge. He fitted it next morning and the car was fine for a week or so until the same thing happened again.
I thought it might have a parasitic drain on the battery so checked it. Result was about 5 mili amps which I presume is the radio memory.
Recharged the battery again and again it was fine for three days when it refused to start again.
Checked the voltage and it was about 12.1volts but the engine would spin over but not start.
He took it to work and tested it again and the battery came up as faulty so it was replaced.
It happened again this morning and again it started the moment the jump leads were connected.
I did check the voltage when the engine was running - 13.6 volts on the old battery - i was expecting 14.4 easily.
Decided that a new alternator is due.
Now the dilemma, do I fit the 45amp unit which is apparently the standard or the higher 70 amp unit.
The battery is an 063 which is rated about 44ah.
Would the 70ah alternator damaged the 44ah battery.
The car does not have any extra accessories such as spots or high output ICE. It is more or less standard.

[mingy]

I would fit a standard alternator if the electrical load is normal ie: no spots, ice etc, i have a standard alternator charging a 72ah battery which runs a 1380cc with four spots and it bangs out 14.5 volts which may not fully charge the battery but when i use the lights and all four spots, the wipers,and the heater blower it drops the voltage somewhat but still just manages to keep between the "off charge" and "on charge" section on the smiths volt meter in the car. 

[KernowCooper]

45amps is fine if the cars standard and a bigger output alternator wont damage your battery, if you do upgrade to a 70amp one then you need to check the thick brown wires from Alternator to Solenoid are able to carry the extra current

[Brigbeale]

45 amp it is then. Are the ones from Minispares any good. I can get a Lucas branded one locally at EuroCarParts but I will have to make sure it has the pulley fitted.

[KernowCooper]

Minispares have been supplying them for years, not see they have any serious issues ? odd one or two maybe but thats the same with anything you sell in quantity, even new BMWs go wrong. Just check with eurocar parts what theirs are in terms of rebuilt etc

[Dusky]

I can vouch for minispares.

I was so unlucky that I got a bad one from them, but they instantely replaced it. BIG A+ service from them :)

[Brigbeale]

Got one from Euros.
They got it from Basingstoke to Bournemouth within 4 hours on a Saturday - fantastic.
Picked it up - slightly different in shape but mounts looked the same - now wishing I hadn't bothered.

The mounting tab spacings are slightly different so had to move the mounting washers to get it to line up on the pulley which is fair enough.
Went to plug the electrics in and found the problem - it won't fit properly!
Firstly the plug rubbed the side of the hole where it goes in making it very tight. I thought at first it was the new terminals.
Secondly the plug will not push fully home because of the damned great aluminium protrusion where the bearing is housed. The wires on the plug come out at right angles.
I could dismantle the plug and fit the wires individually, but I'm a bit of a stickler for correctness and to be honest it would appear bodged.

Rang Euros to ask if it was the correct alternator and was told that was the only one listed. I told him it was different to the original as the plug will not fit.
He said they were now shut and to take the alternator back in on Monday and sort it out then and bring the old unit in as well.
I told him that they already had the old unit and he said that a note would be put on it to stop it being returned to the warehouse.

So now I am stuck with a Mini my son can't use as this alternator doesn't fit properly and Euro have got my original which was working -although not fully- but at least my son could drive it to work on Monday. Now I have to get up at 5.00 to take him to work while I sort them out.
I will probably get a refund and hopefully my old one back and do what I should have done in the first place and order one off Mini Spares.
Rant over!!!
Will try to get some pics up of the supposed replacement.

Edited by Brigbeale, 10 January 2015 - 05:02 PM.

[Brigbeale]

Photos of the 'replacement' alternator.

Please forgive the photos. For some reason, the photos have been flipped up side down when they were posted from my IPad.

Attached Files

•  image.jpg   65.33K   21 downloads
•  image.jpg   50.76K   18 downloads
•  image.jpg   70.48K   13 downloads

Edited by Brigbeale, 12 January 2015 - 07:06 AM.

[Brigbeale]

Have taken the above item back to EuroCarParts and have got a refund along with the original item back as they couldn't promise a like for like alternator.
Refitted it to enable my son to use the car until the new alternator is ordered and fitted. Tightened up the connectors on the plug as it slid on too easily. Refitted with a firm push and clipped in place.

Checked all with a volt meter and it appears to be charging better than it was originally.
New Halfords 4 year warranty Calcium battery charged up And left for 24 hours to settle reading 12.9v with the terminals connected.
Started the engine first attempt and whithin 30 seconds voltage had risen to 14.2v - not perfect but nearly there.
Turned on headlights and voltage dropped to 13.5v.
Turned heater fan on as well and voltage dropped to 13.2v

Now, with the improved voltage and the above info, I don't know whether to fit a new alternator or see what happens.
Should the alternator be putting out 14.4v or thereabouts regardless or are the above voltage drops acceptable?

Edited by Brigbeale, 12 January 2015 - 09:30 AM.

[KernowCooper]

The test is that a alternaotor should charge between 13.7-14.3v any higher it can burn off acid from a lead acid battery and lower than 13.7v it wont charge a 12v battery fully. you will get a small amount of voltage drop but by turning on other item like headlights,etc you should take the revs up to 2500rpm and then take a reading where you woulf expect the voltage to be above the minimum charge voltage of 13.7v, but the better way to check for charge under maximum load is to ensure there is amps going into the battery, the easiest way to do this is with a DC clamp amp meter on the battery + cable.

 

So to summerise, if at 2500rpm with just the engine running your getting 14+v then the alternator is able to charge the battery, now repeat the test with everything on and your looking for the DC amp meter to still be showing + amps going into the battery, -amps means even though the alternator can keep up with the demands under light load, under lights on full load and accessories your drawing amps from the battery and its not being charged, so if you see -amps under full load the alternator is not charging at full capacity and indicates a alternator fault and then should be replaced.

 

As a footnote lots of the replacements now are available in the same fitment as original such as this one here from Minispares http://www.minispare...|Back to search