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[Joe the fish]

Hi all.
Bit of a strange one, went out yesterday for approx 50milr journey stopped and started three times while the out on the last time clicked like a flat battery after being stopped for less than five minutes. No other signs of battery issues until then. It jumped straight away with no issues and then drove the 50mile trip home without problems. I assumed battery and replaced it with a brand new one. This morning started fine did 20miles to work restarted later for another 10 mike journey then again for a 25mike trip. Again got back in after less than 5 minutes and completely dead. Jumped fine and drove 25 miles back. Now battery completely flat again but will jump first time and drive normally.
I am assuming alternator is putting out charge or I shouldn’t have made any of the trips after jumping but it’s xlearly not charging the battery. So something in the charge circuit?
Battery connection is all good any thoughts on where else to look?

[Lizzie Zoom]

When something similar happened to me it was many years ago in a Ford Cortina.  I was driving along and all power went, with the radio first cutting out, then everything else.  It turned out to be a faulty alternator.

So, if the engine kept running until you parked up, then would not restart after a delay, it sounds to me as though you are losing the charge in the battery that you say is now new.  Something is being "left open" for it to discharge like that, and if it is not the alternator (which I would still check) it is to do with the regulator or a short on a circuit.

Others no doubt will give more specific advise

[Joe the fish]

Thanks I’ll add that to the list of things to check although I can’t think of anything that would drain it on less than five minutes...although I guess it could be draining all day and just got low enough after that particular stop. But would it still drive fine for a prolonged period?

[Nick W]

Stop guessing and use a multi meter.
If it shows less than 13.5volts with the engine running, you have an alternator fault. If it's charging correctly, you need to read the forum guide for what to do next.

[Alnico Blue]

Do the checks in Kevin Woods  excellent guide on starting/ charging diagnosis which you will find  in the maintenance section under ICE/Electricals  . . .external electrics sub section . 

[Joe the fish]

Cheers all,
Yes multi meter would be a wise move but I’m at work racking my brains without one
Guess some diagnosis tonight when I get home

[Shackeng]

Stop guessing and use a multi meter.
If it shows less than 13.5volts with the engine running, you have an alternator fault. If it's charging correctly, you need to read the forum guide for what to do next.

I'm assuming that the OP asked because he wasn't sure what to check, so while your advice is sound, it could have been delivered in a more courteous manner, rather than your usual peremptory (ie Why don't you know?) tone.

[Doctor Gollum]

Kevin Woods guide on the subject is fool proof and works on any vehicle 

But you will need a multi meter...

Could be a current drain somewhere, but the guide covers this

[Joe the fish]

Thanks all,
Guide read just need to get home and find the multi meter now.
Dont worry no offense taken.

[TheBoy]

As others have suggested, Kevin Wood's guide is the one to follow, as there are 3 likely causes:

Shagged alternator
Shagged batt (despite being new)
Intermittent high drain, eg stuck HRW relay.


The guide will take the guesswork out



Now, I'm sure your boss is paying you to work, not sit on internet

[aaronjb]

Now, I'm sure your boss is paying you to work, not sit on internet

Hi, pot! 

[robson]

I had very similar thing Greenshag checked my alternator output and said it was ok .next day flat battery .Put new alternator on problem gone.

[TheBoy]

Now, I'm sure your boss is paying you to work, not sit on internet

Hi, pot! 

Nah, I'm a good boy, very rarely touch OOF whilst at work (lack the time), only if I see a load of mod reports coming in

[Joe the fish]

Like a good boy I didn’t use works internet but finally got the multi meter on it tonight battery ok. Alternator reading 12.1 - 12.3 regardless of revs and measured direct off terminals at back of alternator. During test volts dropped to 0.4 twice not unconvinced that wasn’t the multimeter but either way suspect alternator so it’s now off and will get dropped into the local test and refurb place tomorrow.

[cam.in.head]

The voltage even directly at the alternator cannot suddenly drop to 0.4 whilst it has a battery connected to it. By all means have the alternator tested if you realy wish but sounds more like a bad connection somewhere to me.

[Joe the fish]

Like I said I’m not convinced the voltage drop to 0.4 was anything other than the multimeter, so pretty much disregarding that for now. The voltage output from the alternator was still low at barely over 12v regardless of load or revs. Double checked the questionable multimeter on a known good car (my dads brand new Mazda) and readings for that were 14+ volts as expected with a decent alternator.
So still settled on alternator shagged but won’t hear back from the repair place till next week now. Not ruling out anything additional but I’ll be chasing my tail lookin for anytelse with a dodgy alternator.

[Kevin Wood]

Often alternator failures are down to a failed regulator, and pattern replacements can be had for £20 or so. Hopefully the refurb guys will fit a new one.