battery charging problem

[dxi310]

Hi new to the club having purchased my 480 celebration No 202 in November last year -- a 2 owner car with just 51000 miles on the clock and in A1 condition I could not resist her.

However I seem to be encountering problems associcated with the 480 which i am not too concerned about but it seems several mechanical items could be up for renewal at this mileage, however:

Solved the problem of leaking water by ensuring I park the car reversed into my drive ( slightly downhill)

Solved the problem with brakes by fitting new front disc and pads

But i am struggling with the charging system - battery seems to last for various periods of time and had to be rescued on one occasion due to battery falure, by chance the RAC man used to own a 480 and advised the alternator was chargeing ok but it was not getting full output to the batterry? he was sure there was a fuse somewhere in the circuit but was unable to find it, i decided to buy a new alternator and after fitting it was showing a good charge to the battery but after 2 days the battery went flat, the battery is new and i have even subsituted it for a known good one, second RAC man checked and confirmed the alternator was not charging the battery, he also could not find what he thought should be a fuse in the loom and felt it was unlikely that i would have 2 alternators - i new not chargeing

Any suggestions or advise on this mistery woukld be appreciated

Dennis

[glasgowjim]

They will be refering to the mega fuse maybe?

You cant miss it it is massive as far as fuses go except it doesnt look like a fuse holder

Right you are standing at the front of the car with the bonnet up

look at the alternator and locate the positive feed (the big wire ) then follow it back towards the battery you will soon (20/30 cm) come to a black plastic L shaped moulding big wire runs in and big wire runs out then about 30 cm later it goes into a socket.

The big black L shaped housing holds the mega fuse.

I can supply a spare if needed but I would be surprised if it was that.

try checking the mega fuse first if you must.

Now having got that out of your system the next thing is to actually check the size of the battery drain attach a multimeter between the negative terminal of battery and the earth strap make sure its set to 10A range then after that you move down the scales to get the most accurate reading. Now post up results.

Next set reconnect battery and reset the multimeter to 20 v dc range and connect across the battery start car and let it tick over what is the reading on the meter then post up here.

hope this helps

[dxi310]

Many thanks for your swift response

Ran out of battery again this AM but i have been carrying a spare battery in the boot so changed at side of road during rush hour and got going again

I will indeed try all your advise and get back to you

Regards

Dennis

[dxi310]

Hi

Managed to get the car to my usual garage and Steve confirmed the mega fuse was ok, so tested the alternator for output and it was zero

Contacted the suplier and was advised to purchase another unit and return the original to them for testing and refund if found faulty ( yet to recieve the refund)

Steve fitted the new - new alternator and tested on tickover as suggested and the result was 13.63 V rising up the scale as revs rise

So all seems fine and it just goes to show if your replacement unit comes in an unopened box as mine did it might just be a unit that was returned faulty but just put back on the shelf insted of being repaired

Thanks again

Dennis