Alternator woes - any suggestions?

[j-j]

I dropped off my mate at the airport this morning but was nervous that we wouldn't make it... Yesterday I noticed a noise from the engine that sounded like a duff bearing or something - some sort of low whine that varied with revs. All seemed to work OK though - I thought it sounded like it came from near the alternator (a NOS off the shelf item fitted 3 years ago and has done less than 30K miles since) but not sure. Forgot about it for a bit in the true autoshite way as nothing seemed affected.Yesterday evening however I noticed the battery meter on the dash was reading -ve i.e it was reading in the 'red' - I guess the equivalent of the red batt warning light on later cars. Hmm, but all seemed ok - still making the noise and a mild electrical burning smell noticed (!) no smoke seen. All things (except battery gauge) seemed to work OK. Suspect alternator regulator (remote type) pull it off and there's a change - the engine revs increase and the 'bearing noise' vanishes - it's like something is making a right big load on the alt - but everything's off? Connect again and noise back ,revs down. Give up until daylight sometime.Up this morning at 7 for airport, starts up first time all stuff working but batt meter still in red - doesn't raise out with revs or anything. Set off anyway, pick up my mate, get his ass to fook off to NZ as arranged and return to the CX in the Airport crappark (paying £7 for the privilege) start engine but this time starter a bit slower than before - luckily it starts OKBack home after a stop at machine mart to get a multimeter (I know! all these years driving shite old cars and only now do I get a wires tester!) car starts again OK.Back home and switch off, lunch etc.Go to investigate finally what's going on - test battery = 12.65v with engine off. Go to test with engine running AND...... cronk! starter turns over slow as and doesn't start - 2.5cranks more and there's not enough juice to turn it.Shite - it's at the top of a drive nose first! cant get jump leads to reach and no charger! Can't test alternator output yet so check wires.Tested all the connections and earths for continuity - alternator gets battery voltage at connection: check. exciter gets batt voltage with ignition on:check.Check voltage regulator wire to exciter for continuity: OK, earth: OK, 12v supply with ignition on: OK So I suspect the alt has a problem - but like I say - it's technically 'new' ..?I still wonder about the noise like there was mega load going through it but there was nothing? I disconnected the battery and no spark at the terminals so no closed circuits (apart maybe from little dashboard clock)ANY IDEAS CHAPS AND CHAPESSES??

[Rocket88]

Sounds like borked alternator. When you get it running you should get about 14.2 volts output from a healthy alternator. Alternatively [ho ho ho] slip the belt of, if no noise, it's bollocksed.

[seth]

A NOS item might have been fitted only 3 years ago but its still 20-30 (?) years old and after 30k miles could come to its end....

[j-j]

Thanks for the fast response - yea, it's what I thought but will need to confirm - shame as it really was a NOS unused part O well, hopefully it is the cause so that it's easy to remedy - I still have the old alternator originally fitted but not sure how old it is. Anything to get it going. Why the hek did I park it nose first up a drive when I knew something was iffy about the alternator?? Only I can answer that question - cos I IZ A TOOL INNIT.OK, cheers will report on my findings for your immense entertainment (BTW it stopped making noise and burny smell now that it seems to be doing nothing (while engine running that is))

[j-j]

A NOS item might have been fitted only 3 years ago but its still 20-30 (?) years old and after 30k miles could come to its end....

Could be - I had this with a 'new' fuel pump years ago - inner diaphragm was mullered despite nice shiny appearance.

[M'coli]

Check the earth between the alternator and the block - use jump lead temporarily. However, be prepared to fork out for a recon job though.

[j-j]

Check the earth between the alternator and the block - use jump lead temporarily. However, be prepared to fork out for a recon job though.

-Would this be earthed via the mounting?

[M'coli]

I would assume so, it could also earth through the adjuster.

[Richard]

Check the earth between the engine and car body, and all the connections leading to the battery, before you consider spending money.

[j-j]

Right will check these first next oppo

[Richard]

As M'coli has suggested, some alternators are rubber mounted and require a separate earth wire. I don't think yours will be but it's something to check.

[j-j]

Will do guys - cheers for all the help

[Lord_Isleworth]

BTW I know of a decent guy in Surrey area who does refurb alternators etc...I could dig out his number if you need it. Really knows his stuff and helped me out big time when I had my old Beemer. You can send the part to him and he refurbs it

[j-j]

Sounds good LI, will do if I find the thing to be mullered

[nigel bickle]

If thats the chap in Horley-I concur. Recently turned a wrecked 6v starter into a nice shiny 12v runner. (Something Bosch -the manufacturer,couldnt do) quickly & at a sensible price. Good luck

[Rod/b]

Can I suggest you get the battery checked first? I had a goosed battery in the Audi and it was causing the regulator in the alternator to get confused and vary it's output all over the shop.

[Lord_Isleworth]

The guy i have used is John based in Hook Rise near Kingston. He has over 30 years experience and does anyhting from old cars/vans etc...anything that moves really. 020 8391 1004

[j-j]

Thanks very much I'll keep note of that. I managed to get it going this evening with a charge of the battery and swapping back the old original alternator - starts, runs and charges - 14.5 volts at 1500rpm, 12.5-13 stopped. I had a look at the 'faulty' unit and tested the connections and the 6 diodes (big old skool diodes!) and is seems OK too but the point where it earths was not clean - actually it was fooking manky, not least due to the copious amount of grease I'd applied there a year or so back to stop the mounting bolt ever rusting in - it has attracted quite a lot of crap...Testing the earth contact showed it was poor due to the rubber vibration mounting having collected lots of oily goo. It was stopping the contact between the metal inner part of the rubber bush and the outer bracket and While the other end was still a good contact (threaded end of the big bolt) as it has no rubber bush, it was the dirtiest bit so I think the combination of all this oil/crap was affecting the earth of the alternator but I'll know for sure only when I refit the 'new' unit. Keep it running on the old one for ethe time being.Thanks for all the help folks - much appreciated