Alternator failure - might there be other damage?

[Flat 6]

My alternator failed yesterday (charge light permanently on with ignition not on). 

I've never experienced this kind of failure before but man does it drain the battery...there was so much current running through the earth wire going from the alternator to the engine case that the wire heated up and started to smoke at the end connected to the alternator.  Thankfully I was at home and was able to disconnect the battery quickly.

So, I've removed the alternator from the car.  In doing so, these parts fell out of the alternator...

Anyone know what these parts are?  Only for interest - not intending to have a go at repair myself.

I may try to get the alternator fixed locally but in the meantime I'll just buy a replacement.

My real concern is whether or not the amount of current flowing might have done any damage elsewhere on the car.  Presumably with the earth going straight back to the battery via fairly hefty connections, this will have reduced the risk of damage elsewhere?

Any thoughts?

Al.

 

 

[sopor]

Those look like parts of the diode pack.

I wonder if the alternator was fine but a poor earth connection at the alternator itself caused it to "over drive" itself? Has there been any work done prior to this requiring the alternator to be disconnected or the engine to be removed?

Or the diode pack mechanically self destructed and caused a short within the alternator?

[Kenny Senior]

If the insulation on the cable from the alternator to the starter is still pliable and not crispy then I wouldn't worry too much. The failure was in the alternator. The most likely explanation is a diode has stopped blocking current in the reverse direction and effectively created a short circuit to earth. The bits in your last photo couldn't handle that much current and were the first bits to melt (or what they were attached to has). Worth checking your grounding strap too, but I'd just swap the alternator for a new one and use your old as the exchange unit.

[Flat 6]

Thanks Gents,

Car's been running well since engine was rebuilt and reinstalled 2016.  

Hopefully a new unit will sort things.

Al.

[Nige]

When you get it fixed up check the voltage regulator as well.

[Jonny Hart]

Flat6, you'll probably be ok but just double check the alternator earth strap and positive cable to the starter.   I've done some pretty 'hairy' experiments with custom alternators in the last couple of years.  Have set fire to a couple!  

I'm now running a custom 175A unit which delivers ~80A at idle and I've had 145A out of it on the standard single pulley.  These will be available in a month or two with any luck.

[Flat 6]

OK, thanks Gents. 

Electrics are not my forte...when you say 'check voltage regulator ' in this car it is built into the alternator. I have found a kind soul who will repair in 24hrs (deadline due to photo shoot with mag on Wed!!!). Presumably they will check voltage regulator as part of repair?

Ref earth straps, starter is strong and car starts immediately. How do I test earth straps? Current down earth wire from alternator to battery negative cable?

Lastly, just in case the repair place isn't able to meet deadline (like if they needs parts they don't stock),  I've been offered a 964 alternator still in its housing. Is this likely to be of any use to me??

Cheers,

Al.

[Nige]

Get you refurbed alternator installed.  If you've got considerably more more than 14.4V at the battery (check with a voltmeter) with the engine running then you may have an issue with the regulator.  Not sure if they are internal or external to the alternator on your car.

I had a 76 with an external regulator which had a faulty earth, as such it didn't regulate.  I only realised after getting a sore throat from boiled off battery acid, I could hear the battery fizzing.

[Leicestershire]

'78 should be external.

ECP were knocking the BERU regulator out for £20 last time I purchased one.

 

[Flat 6]

Apologies. Should have mentioned that this is an '83 SC that I have temporary custody of.

So regulator is on the alternator. 

I've just left it off at the repair place and will hear later whether or not it can be fixed by cop tomorrow. 

Also visited a local indie who had a non regulator alternator and a Bosch from a 964 but I now know neither of them will do...

In the lap of the Gods...

Al.

[Type911]

The external 911 and 964/993 version wont be any good for an 83 SC

We have the correct version in stock

Edited April 16, 2018 by Type911

[Flat 6]

Thanks Matt,

Picking up repaired alternator tomorrow. 

£180 plus VAT for repair. How much would I have been splashing for a new one or a refurb etc. There look to be offerings from Lucas, Bosch? Valeo no longer available? Mine is a Valeo - is that OEM?

Hope rest of car is OK. I'll be watching a voltmeter as the car is started!!

A.

Cheers, 

Al. 

[Type911]

£180 is good, ours are £295. Valeo recon units. The problem is finding the old units to recon, like brake calipers.

[Busybee]

Not sure if my old alternator could be rebuilt. It’s a Valeo. The shaft is stuck so maybe the bearing has collapsed or the shaft has dropped into the windings. Who’s rebuilding yours @Flat 6?

[Flat 6]

 

46 minutes ago, Busybee said:

Not sure if my old alternator could be rebuilt. It’s a Valeo. The shaft is stuck so maybe the bearing has collapsed or the shaft has dropped into the windings. Who’s rebuilding yours @Flat 6?

Mine is being done by a small company in the middle of nowhere in a place called Cookstown here in N.Ireland.

I guess you could post yours to them and get them to look at it but they might then not be able to fix it and they would then have to ship it back to you.  Not might things alternators as you know...I suspect you would be getting closer to Matt's price by the time you paid for shipping back and forth to N.Ireland.

I'd certainly hold onto yours - useful as an exhange unit.

Al.

[SilverWT]

17 hours ago, Flat 6 said:

£180 plus VAT for repair

Sounds expensive to me, rebuild and refurb cost me £100 inc VAT two years ago. It looked like new and has worked perfectly...

 

[Busybee]

2 hours ago, SilverWT said:

Sounds expensive to me, rebuild and refurb cost me £100 inc VAT two years ago. It looked like new and has worked perfectly...

 

Come to think of it, I bought my Dansk new replacement alternator last year for around £250 I think. Higher Amp and on board regulator. Been working well since install. No trade in so I have my busted Valeo to hopefully get refurbed and keep as a spare. 

[Flat 6]

I'm not surprised. Lack of competition here in N.Ireland and they knew I was in a tight spot. 

But NI can be lower cost for other things. Anyway, on my way to pick it up so good service. 

Al.

[Flat 6]

Thanks Matt,

Picking up repaired alternator tomorrow. 

£180 plus VAT for repair. How much would I have been splashing for a new one or a refurb etc. There look to be offerings from Lucas, Bosch? Valeo no longer available? Mine is a Valeo - is that OEM?

Hope rest of car is OK. I'll be watching a voltmeter as the car is started!!

A.

Cheers, 

Al. 

[Flat 6]

4 minutes ago, Flat 6 said:

So, I think possibly my alternator was wired up wrongly? My fatter brown earth wire was connected to the fan housing by one of the long bolts that goes right through the outer casing of the alternator and then holds the airflow duct in place.

All the photos and discussions I can find online seem to suggest that both earth wires go to the same post coming out of the actual alternator. 

Any thoughts??

Al.

 

[Jonny Hart]

^. Earth cable needs to go straight to alt minus.  Connecting it to the fan housing may work but It isn’t really properly attached to the engine case so bound to be some contact resistance.

[Flat 6]

Right. Both earth connectors on same post on alternator and all back together.

16.5 v at the battery. Regulator is new.

WTF...

Al.

[Klassiker911]

On 17/04/2018 at 19:06, Flat 6 said:

Right. Both earth connectors on same post on alternator and all back together.

16.5 v at the battery. Regulator is new.

WTF...

Al.

Flat 6, did you ever get this sorted? as I appear to have a similar problem although mine fluctuates from 13.5/14v up to 16.5v and back again 

[Flat 6]

Hi there,

It’s five years ago now and wasn’t my car but I think we shelled out for a new alternator. 
 

Your fluctuations may suggest your regulator is on it’s way out? But as I say, electrics are not my thing!

good luck.

Al