another electric problem :(

reet tonigth went for some petrol and my dask light were getting dimmer so was the lights on the road
pulled up and turned the car off looked under bonnet though that the altinator belt may have snapped, was in good order and tight
went to turn the car back on and woudnt start
no charge in the battery
lucky i had a mobile jump pack in the car and it started after i used that
the ligths started to go dim again and the battery light came on
so i started to speed up so i could check there wasnt any loose earths or owt then the lights started to brighten up once i acelerated and stayed like that till i got home

last couple of days ive had to jump pack the car, just though somethign was draining the battery

any ideas?
maybe faulty battery??

cheer jack

if you have a multimeter put it across the +ve an -ve terminals on the battery, with the engine running you should see around 14v (or just under), if it drops withe the engine off then the batterys not holding charge i.e buggered (true tech term there lol)

if its low with the engie running alternators bugged,

if you havent got a multimeter pop to your nearest kwik fit (free plug) an they'll test it for nowt, all kwik fit batterys(although dear) cum with a 3yr garentee which no one else does.

hope this helps  pete

Sounds like alternator is okay but battery is flat. Ideally what you need to do is give the battery a slow trickle charge overnight, or something, then wait 12 hours (to eliminate surface charge) then check its voltage, to see if it can retain the charge. It is possible that if it went flat ONCE, this has damaged the cells so it now cannot retain charge for any reasonable length of time.

cheers lads
i have a 3 years gaurentee on my battery atm
might go get it swaped and see what the score is after

Sounds like earths buddy, easiest thing to check 1st anyway though.

1. disconnect battery
2. put test meter onto negative battery clamp
3. put other end onto shiney top of engine

Check resistances, they should be between 0-2 Ohms

Otherwise you maybe are overloading the alternator, or maybe its not charging, not liekly to be overloading unless your running a couple of amps, charging is easy to check but check the earth 1st, take it off give it a good clean and scrub all the surfaces it connects to.

Isopropynol, PCB cleaner/Rubber, brillo pads are all good for cleaning up the other. DO that and we'll take it from there.

think i may have found the problem
my battery was faulty but i got it changed

ive only realised
it does it when the stereo, sub and amp
maybe this is the problem????

Jack1 said

think i may have found the problem
my battery was faulty but i got it changed

ive only realised
it does it when the stereo, sub and amp
maybe this is the problem????

which amp have you got you could be drawing a lot of current. especially with it turned up (and the bass high)
you may need to put a capacitor in the power line to deal with the draw.

Check to make sure you dont have it permantly connected, there should be a terminal that turns the amp on when your head unit is on, this is connected via a relay from either your head unit (Preferable) or from the ignition.

Depending on the wattage you may need to upgrade your alternator and /or battery, i've mentioned about 800w with a 65amp alternator on other posts, not 100% sure about that figure as its not a black and white thing, different music types will draw different powers, as will different songs.

Also some are more effecient than others too which complicates matters.

A capacitor across the voltage rails, will help a bit but probably wont stop it draining, and unless you get one of those expensive power caps your probably not going to get any improvement at all.

It could still be your earths and unless you make sure they're good we wont get much further.

right then
ive forgot what my amp is hahaha
my minds gone blank
ill try and remember now
or ill just go and lookinabit

anyways its when bassy music (drum and bass) but seem to be fine when i have slipknot on hahaha

the power line for the amp is connected to a switch so it isnt on all the time

what is all this speak of a capictor?

and all the earths are good and tights
i checked them yesturday and also when i changed the altinator

cheer jack

in basic form fella an amp requires more power to generate bass.
a power capacitor (which is what i was talking about) basically stores some of the power the amp will need so not as much is drawn from the engine at once.
the reason i asked about what amp is so we can give you advice on whats happening. but by the sounds of things your taking more power than the engine can give.
you could try turning the gain down on the amp which should make it a bit more effecient.

sorry about the late reply
been ok till today when i was playing guns and roses
turned the car off and turned it back on
the engine didnt turn over
put bump pack back on
keeps doing it

the amp is a alpine MRH F255
specs from the website
Alpine Amplifier Model # MRH-F255
Slim Line Design, Duo-Beta Circuitry,
Gold plated terminals 4-volt inputs, stable into 2ohms
Four Channel + Subwoffer Channel
First four channels are 35x4 watts RMS, 70x4 max, they
have a switchable (on/off) high-pass crossover that is
continually adjustable from 10Hz-50KHz.
The fifth sub channel is 80x1 watts RMS, 160x1 max
with a continually adjustable low-pass crossover
from 10HZ-50KHz

and the sub is a 12" ifinity
carnt get any specs or name until i take it out and have a gander at the bottom
cheer jack

i'd say your alternator and batter are knackered mate if that amp is draining.
either that or it's not fitted properly and is causing a serious drain.

You could just turn the stereo down then? Ideally, sounds like you need a higher capacity alternator. Also worth considering is a second battery and a split charge relay. Basically this means that the stereo and amps (and any other non-essential electrical items) could be powered through this battery, leaving the main one to start the car and serve the essential electrical stuff. Many modern cars these days are twinned up like this, also motorhomes, caravans, etc. Just make sure you get a decent split charge relay and make sure its wired off the alternator warning light, so that it will split the batteries during starting (if not, it might overload the wiring).

or stick a cap in the boot.

or say see ya later to sub and amp? hahaa
the battery is brand new and the altinator is newish

Jack1 said

or say see ya later to sub and amp? hahaa
the battery is brand new and the altinator is newish

How powerful is the amplifier? What rating is the alternator? What other non standard electrical items does the car have?

this is teh only thing i can find about it;

the amp is a alpine MRH F255
specs from the website
Alpine Amplifier Model # MRH-F255
Slim Line Design, Duo-Beta Circuitry,
Gold plated terminals 4-volt inputs, stable into 2ohms
Four Channel + Subwoffer Channel
First four channels are 35x4 watts RMS, 70x4 max, they
have a switchable (on/off) high-pass crossover that is
continually adjustable from 10Hz-50KHz.
The fifth sub channel is 80x1 watts RMS, 160x1 max
with a continually adjustable low-pass crossover
from 10HZ-50KHz

it doesnt evan say on the amp either
just the name and model

theres headunit, some 4 inch speakers in the door and sub and amp
i put a switch in for the raditor fan as it wouldnt start on it own
thats about it

Turned up, the amp probably draws 500-600W power at peak, and 250W or so on average, so this is going to demand an extra 20A of current over & above the other electrics on a car. Its a small block, right? Probably too low a power alternator for your needs, so you need to upgrade it or turn the stereo down, otherwise you're going to keep getting flat batteries, since the amp + electrics is drawing more power than the alternator can supply.

Can you find out the spec of the alternator fitted?

yer its a small block
ill tryand get out when it aint raining and have a gander
i havent had the setero on recently and i drive to the other side of the city everyyday for work and after it still require a bump starter
i have a feeling that the atinator is poo

pete_n_mel said

if you have a multimeter put it across the +ve an -ve terminals on the battery, with the engine running you should see around 14v (or just under), if it drops withe the engine off then the batterys not holding charge i.e buggered (true tech term there lol)

if its low with the engie running alternators bugged,

Did you do this check? If so what are the exact voltage readings?