Not holding charge ?

[gazzab]

Changed the battery a few months ago, been driving the car very regularly on longish journeys, changed the fuse yesterday, charged the battery up for a couple of hrs......
Went for a drive and after 5 or 6 miles the rev counter stopped working and the car struggled home , it now has a reasonably flat battery.
The battery light didnt come on.
Any ideas? I guess it might be the alternator?

[headcase]

Could well be the alternator! To check its output you need to charge your battery then fire it up again then measure the voltage across the battery, it should read 14.4(ish) then turn on as much electricals as poss (headlights&heater fan is best) then re check, the voltage souldnt drop more than .2v. You also need to check the connections properly as a dodgy connection could cause a similar fault, also you mention the fuse I presume you mean the 100A (big) fuse, again make sure the connections here are good. If it is charging ok then it can only be the battery.

[Byff]

When my big fuse popped, the replacement lasted for about a week before I got the rev counter packing in again. For all the big fuse looked ok, I still replaced it and everything has been fine ever since.

All I can put it down to was one of the prongs had twisted a tiny bit when tightening the bolt down.

[gazzab]

I guess I will try the big fuse again first of all and try the battery test.
I put the new fuse on top of the 'leads' and under the nuts. Guess I Could have overtightened and not got such a good contact. could call the AA as I have the warranty that would cover a new alternator.

[gazzab]

Helllllpppp
Charged the battery at the weekend. since then I have simply moved the car in and out the garage so it should be pretty topped up still. Started it just now, turned over very well and fast n keen.
Checked the voltage at idle - hmmmm 12.2 - 12.3 !! not 14.4
Turned on aircon and lights and drops to 11.9 ish.
Confused !!! Think it says to me that the battery is stuffed. Less that a yr old (thanks Halfords!). Anyone else got a view ?
I dont think this points to fuse or alternator.
Any views before I pull battery out (PITA) and/or before I call the AA?!?

[dean_ratpac]

if less than a year old, get it excahnged under warranty

[Seasider]

Does the battery light come on before you fire the car up ??

[gazzab]

Yes battery light comes on before I fire her up and then it stays off.

[gazzab]

dean_ratpac said:

if less than a year old, get it excahnged under warranty

Can do - but dont want to go the pain of that process if someone says - nah its probably the fuse (changed 3 times !) or the alternator.

[Steve_T]

If the alternator is charging the battery properly, the voltage is typically north of 13v. Either it's big fuse (the old favourite hairline stress crack perhaps) or a dead alternator. Hope it's the former.

Steve.

[Seasider]

gazzab said:

Yes battery light comes on before I fire her up and then it stays off.

I know if it doesn't that is a sign of a dead Alternator & the test is take the smaller + off and earth out to see if the light works... but not much use for you

[gazzab]

So it might be he fuse, the alternator or the battery!
I will charge the battery again and see if it goes over 13 volts. I thought it should be over 14.

[betty_swallocks]

Check the battery with the engine stopped, should be about 12 volts, then check with the engine running, should be 14 volts
check the output either side of the big fuse, should be 14 volts (with the engine running), if the alternator side is 14 volt and the battery side is 12 then you have the answer
if they both show 12 volts then get the alternator checked by a auto electrician, they can usually rebuild them without buying a new one

[Captain Beaky]

It could also be the alternator drive belt - mine has just gone but hopefully the alternator itself is OK. The symptoms are the same as a failed alternator.

You can see the belt if you peer down below the inlets towards the front. You might need to remove a purple pipe to see clearly.

[gazzab]

betty_swallocks said:

Check the battery with the engine stopped, should be about 12 volts, then check with the engine running, should be 14 volts
check the output either side of the big fuse, should be 14 volts (with the engine running), if the alternator side is 14 volt and the battery side is 12 then you have the answer
if they both show 12 volts then get the alternator checked by a auto electrician, they can usually rebuild them without buying a new one

thanks b_s!

engine off = 12.4
idle = 12.2/3 ish
under load = 11.9
SO starts to sound like my alternator ie not getting battery power up with engine running. ie no point in testing either side of the fuse if battery is only showing 12 v's.
ANSWER = call the AA as I have the warranty and so a new alternator would be covered?
Need to call them tomorrow - but need to breakdown first !
Will have another try in a min.
thanks for the advice.

[headcase]

Yep, does look like the alternator to me.

[gazzab]

A mechanic friend of mine suggested that the alternator is ok if I get over 13.7 at 2K revs. Well I got 13.99 volts. So maybe it isnt the alternator. Any views?
Now the battery has had a full charge and I have refitted the big fuse then maybe all is ok finger crossed).
So I might see how it goes for a few days - just dont want to breakdown !

[gazzab]

Did two 18 mile journeys today (one with a couple of stops) - so all bodes well for the bug fuse and a full battery charge solving my probs.....!?