Alternator & Battery Light Woes

[shed_racing 0]

Morning all,

 

As the title, really; did a cambelt and pump replacement last weekend, put it all back together and forgot to tighten the bottom alternator slide bolt

 

Hooning down the A1 Tuesday morning and there was a bit of a bang and a rattle and the bloke riding right on my bumper suddenly back off a bit ! Must've been the M8 bolt and washer bouncing off his bonnet !!

 

Anyway, on the way home the lights were dimming all the way, slow wipers etc. but no battery warning light.

 

Ran a multimeter across the battery and the alternator was not charging.

 

New alternator fitted last night, and (after tightening up ALL of the bolts !) went for a spin; all good, except on the way back, the battery light kept making an appearence; flickering, low then bright, then off - mostly over 4k. Thought that it was a loose connection, so deliberately drove over the off-road section of our local highways (resultant potholes from the last splash of snow) with no influence on the light coming on.

 

Aha, I thought - must be the new drivebelt bedding in, getting warm and slipping a bit. Got home, multimeter said 14.6 or so, so I tightened it up a tad and went merrily off to bed.

 

On the way to work this morning, the light came on and stayed on

 

Anyone got any ideas, please ? Electrics are really not my bag (see previous posts !)

 

Just to confirm, exciter wire's on and all good, and the main feed is nice and tight and covered with copper grease . . . .

 

 

Thanks guys.

[Anthony 1,003]

Exciter wire shorting out on the engine block or something? Earthing the wire out will cause the light to come on.

 

Of course, don't make the mistake of assuming that a new alternator actually works properly... with the light on all the time, is it still charging at 14.x volts?

[shed_racing 0]

Aha !!

 

Hadn't thought of the little brown fella shorting - will check the output. No MM at work, so it'll have to wait 'til this evening.

 

The alternator is a GSF special, and came with it's own birth / test certificate, so I'm hoping it's a "good" one (well, when I say good, it's all relative)

 

Thanks Anthony

[Paul_13 212 1 Cars]

Does the alternator have to be earthed on 8v blocks, mine never was but when I did it ran better.

[Anthony 1,003]

Does the alternator have to be earthed on 8v blocks, mine never was but when I did it ran better.

It earths through the alternator body, through the engine block and gearbox, and to the battery via the gearbox earth strap - same as a 16v.

[Paul_13 212 1 Cars]

Getcha...

[shed_racing 0]

OK - so, when all is said and done, if I continue to drive the thing with the big red battery light on, am I likely to kill the new (£83 !!) alternator ?

 

(Please say no !)

[Anthony 1,003]

OK - so, when all is said and done, if I continue to drive the thing with the big red battery light on, am I likely to kill the new (£83 !!) alternator ?

Shouldn't do so long as the main 12v wire is definately properly connected. I've no idea if it would actually damage an alternator with that loose/disconnected, but I know they explicitly warn again it.

 

However, if the light is on solid there's no guarantee that the alternator is actually charging at all now, so you might run out of run out of battery charge on the way home. With no multimeter, a quick test would probably be to see if the headlights seem any brighter with the engine running (and theoretically 14.x volts) compared to with the engine off (and theoretically 12.x volts) - if they do, then the alternator is likely charging.

[shed_racing 0]

Thanks Anthony - last time I noticed it was playing up I switched the lights on and there was no dip in the RPM. (up until then, it dropped about 200 rpm with the lights on)

 

Will nip out lunchtime and give it a go. Oh, and check the main cables still attached !

 

If it isn't charging, I'll go home early, in the light, and hope the rain stops . . .

 

Thanks again.

[Rallyvan 0]

Iv just had the exact same problem, got a new alternator to no avail. It turned out to be the 10 amp battery warning light fuse had blown, thus causing the battery light to come on. Worth a look.

[shed_racing 0]

Well, just got in it at lunchtime - batt light on permanently, slooo o o o w wipers and dim lights, so guessing it's not charging.

 

RPM idle has lifted, too, as if there's no belt on the alternator ? (there is, of course, and it's quite tight, too . . . ) and doesn't flutuate under electrical load.

 

Both leads are on securely, and no amount of wiggling (ahem - adjustment) seems to make the light go out

 

Only option is to check the feed to/from the battery that was moved around slightly on installation of the alternator . . . . .

 

looks like an early bath for me, then !!

 

 

Rallyvan:T hanks for the pointer - I'll check the fuse; did this cause the "no charge" issue too, though ? (it's one in the glovebox, right ?)

[Rallyvan 0]

Well, just got in it at lunchtime - batt light on permanently, slooo o o o w wipers and dim lights, so guessing it's not charging.

 

RPM idle has lifted, too, as if there's no belt on the alternator ? (there is, of course, and it's quite tight, too . . . ) and doesn't flutuate under electrical load.

 

Both leads are on securely, and no amount of wiggling (ahem - adjustment) seems to make the light go out

 

Only option is to check the feed to/from the battery that was moved around slightly on installation of the alternator . . . . .

 

looks like an early bath for me, then !!

 

 

Rallyvan:T hanks for the pointer - I'll check the fuse; did this cause the "no charge" issue too, though ? (it's one in the glovebox, right ?)

 

Wasn't so much no charge, but the charging was all over, is the battery light coming on at the second postion on the ignition, then going out when you start the engine? (as it should)

also if I put full beam on this sum how bypassed the warning light and it would go off as soon as I switched back to dim it would come back on.

And yes it's the one in the glove box.

Hope this helps.

[shed_racing 0]

To be honest, I'd have to check if it goes out on the spring then comes back on on position 2. . . . will have a look on the way home.

 

I might try the hgh beam /low beam thing too - getting deperate now ! (can you tell ??)

 

The chap that helped me with the cambelt last week (and inadvertantly saved me from giving my car a viking funeral. again) is an auto electrics lover, so I may have to fork out for a few more beers and ask him to help me out.

 

Thanks for the assistance - rest assured I'll add the solution, if ever I arrive at one.

 

Cheers,

 

Shed.

[shed_racing 0]

"Thanks for the assistance - rest assured I'll add the solution, if ever I arrive at one."

 

 

 

Well - you'll never guess what ? managed to get her to give me a hand yesterday; after mucho deliberation and cursing, she sat in the car and told me when the batt light came on as I wiggled various leads/connections. Turns out that the exciter lead was playing up after all.

 

So, after re-wiring back to the brown multiplug, turns out that the connector on the recon alternator is loose, and consequently randomly breaks down, causing the light to come on and the barsteward not to charge.

 

Thanks all for you helpful suggestions, and I've made a mental note to self not to trust "new" parts in future ! (someone even suggested checking that the new alternator was good in an earlier reply. . . .moral: never trust GSF !)

 

Back in the saddle now , though, so all's well.

 

Cheers,

 

Shed.

[welshpug 1,657]

funny, that, I've had no trouble with my Hella Remanufactured Alternator from GSF

 

 

had loads of trouble with an alternator from an auto electrical specialists though with a Diesel VW T4 van

[shed_racing 0]

funny, that, I've had no trouble with my Hella Remanufactured Alternator from GSF

 

 

had loads of trouble with an alternator from an auto electrical specialists though with a Diesel VW T4 van

 

 

Must just be a rogue unit I've landed ! (although it's not Hella - can't remember the make, but It wasn't one that I recognised . . . came in at about £64 ?)

 

Being fair, they've been quite good to me in the past - just annoyed that I totalled a weekend thinking it was me, when in fact it was the "new" part !

[happygoron 2]

I've had a duff "recon" alternator from GSF too. Very annoying.

[shed_racing 0]

Well, just spoke to them on the 'phone and they seemed fine about me exchanging it - so . . . new one off again tonight, over to GSF tomorrow lunchtime, and hopefully, new one on again tomorrow evening.

 

Please let this be it, now ! Enough with the little red battery light.

[shed_racing 0]

Well, just spoke to them on the 'phone and they seemed fine about me exchanging it - so . . . new one off again tonight, over to GSF tomorrow lunchtime, and hopefully, new one on again tomorrow evening.

 

Please let this be it, now ! Enough with the little red battery light.

 

 

All sorted - was indeed a duff recon unit.

 

No more light ! Woohoo !

 

Thanks again for all of your contributions