car battery problems

[ryanshelton]

SWMBO has a Citreon Picasso. Its 12 year old and recently developed a few 'issues'. Its only done 90k but weve only had it 18 months.

Battery was replaced a few months ago, then 4-5 weeks ago it wouldnt start after being sat for 5 days. Green flag came, bumped the battery and said it wasnt powerful enough for the car.
Took it to the mechanic who put it in who said its the right one and we trust him. He couldnt work out why it was draining, nothing was left on while it was sat.
He replaced the battery and today, its been sat for 4 days, she goes out to it and no power! Wont start, no central locking nothing. Zilch. Bugger all.
Jumped it from my focus, realised it had no oil so topped the oil up and took it on a 40 min run to charge the battery.
got back home and took the key out, went to start it again immediatly and nothing. Its dead. The battery is only 4-5 weeks old it cant be wanting a replacement already.

Ive left it outside to rust now, in the hope someone steals it. bloody stupid car :evil: :evil: :evil:

 

[bobsbeer]

Sounds like you have a duff battery. You should have a guarantee so you can get it changed. You can get duff 'new' batteries.

 

[ryanshelton]

Sounds like you have a duff battery. You should have a guarantee so you can get it changed. You can get duff 'new' batteries.

but this would be the 2nd duff battery in the same car? Bad luck?

 

[bobsbeer]

It happens occasionally. But I would get your mechanic to check for earth leaks, also assuming your alternator is ok?

 

[Bogwitch]

Does the battery warning light come on with the ignition and go out with the engine running?

If it doesn't come on with the ignition on and engine not running, the bulb could have blown and that could be masking an alternator (or other part of the charging circuit) fault.

It is also worth checking how tight the connections are to the battery, alternator etc. A loose connection could cause this (it's rare though)

 

[ryanshelton]

Does the battery warning light come on with the ignition and go out with the engine running?

If it doesn't come on with the ignition on and engine not running, the bulb could have blown and that could be masking an alternator (or other part of the charging circuit) fault.

It is also worth checking how tight the connections are to the battery, alternator etc. A loose connection could cause this (it's rare though)

Yeah the warning light comes on. Ive checked all the connections on the battery(with my limited car knowledge) and all seems ok. I assume the alternator is ok as it wouldve cut out when driving?

 

[Bogwitch]

Does the battery warning light come on with the ignition and go out with the engine running?

If it doesn't come on with the ignition on and engine not running, the bulb could have blown and that could be masking an alternator (or other part of the charging circuit) fault.

It is also worth checking how tight the connections are to the battery, alternator etc. A loose connection could cause this (it's rare though)

Yeah the warning light comes on. Ive checked all the connections on the battery(with my limited car knowledge) and all seems ok. I assume the alternator is ok as it wouldve cut out when driving?

Does the warning light come on with the car running? If so, there's something wrong with the electrics somewhere, wither a faulty alternator, a loose connection to the alternator or, as Bob suggested, a dodgy earth.

A can can run quite happily with a failing alternator, it only needs enough juice to run the spark plus (not even that if it's a diesel) It will be a different matter if the lights are on!.

If the battery light is off with the engine running, it's either a dodgy connection or a duff battery - or something weird happening!

 

[TRXnMe]

Get a volt meter, check the voltage across the battery: -

1. When the engine is off
2. When the engine is running at ticck over
3. When the engine is being revved a bit.

Voltage with the engine off should be no lower than 11.5 volts (a flat battery, but with all cells 'working')
Voltage with the engine at ticckover should be no lower than 12.5 volts
Voltage with the engine being revved a bit should be around 12.8 to 13 volts, maybe a little more if you had to jump the car and the battery is being recharged from flat.

Alternators can, and do, wear out, 90k miles might have been all town work with a lot of load on the thing so the brushes have gone, if that's the case you might get enough output to turn the light off, but not enough to top up the battery with anything electrical (heater motor this time of year) running.

Also worth trying 1 through 3 with everything turned off, and 2 and 3 with everything turned on, including the lights.

 

[ryanshelton]

Are you sure itd still run with a faulty alternator? Everything on this car is electrical, the whole dash including speedo is so wouldve thought itd die pretty sharpish if it wasnt being charged? Ill check the voltage in the morning, cant get the car to the mechanic till wednesday so I should have a bit more time to investigate

 

[Wol]

Also, worth checking the fuses. Got caught out with that in work after condemning an alternator on a Mondeo st200. Was a ***** to fit, only to find out the fuse had blown. :evil:
Had to refit the old then, so spent most of a day doing what should have been a 2 minute job.

Every single car that comes in now that ain't charging, I'm straight in the fuse box!

 

[ryanshelton]

good thinking about the fuse ill check it in a sec but for now, the plot thickens....

just jumped it again to check it with the lights etc on, as soon as i put the leads on and turned the key the car started, no problem no hesitation.

Took the leads off(was on for no more than 30 secs) it was still running, put the lights on, still running, no flickering or anything that id expect if it wasnt charging properly. Locked the car from inside with the central locking button and the lights dimmed a little. Put the radio on, was fine put the heater on all was well until i turned it up to number 4 and, i was plummeted into darkness.

It mustve taken the juice out the battery and back to square one. Is this sounding more and more like the alternator?

 

[TRXnMe]

good thinking about the fuse ill check it in a sec but for now, the plot thickens....

just jumped it again to check it with the lights etc on, as soon as i put the leads on and turned the key the car started, no problem no hesitation.

Took the leads off(was on for no more than 30 secs) it was still running, put the lights on, still running, no flickering or anything that id expect if it wasnt charging properly. Locked the car from inside with the central locking button and the lights dimmed a little. Put the radio on, was fine put the heater on all was well until i turned it up to number 4 and, i was plummeted into darkness.

It mustve taken the juice out the battery and back to square one. Is this sounding more and more like the alternator?

Sounding like it might be a short on the heater circuit, heater motors don't draw any more power for speed 4 than they do for speed 1, the speeds are usually set by resistors, and you swap from higher resistance to lower resistance supplies as you move the switch (well, the last few of my cars have been like that), being plunged into darkness indicates a fault, possibly one that's the 'wrong' side of the fuse to blow it and protect the car.

What happened when you turned the heater knob away from speed 4?

Your earlier question about the electric dash, if the alternator is on its way out, they yes it'll still run, those dash board don't actually need a lot of power.

 

[ryanshelton]

[/quote]

Sounding like it might be a short on the heater circuit, heater motors don't draw any more power for speed 4 than they do for speed 1, the speeds are usually set by resistors, and you swap from higher resistance to lower resistance supplies as you move the switch (well, the last few of my cars have been like that), being plunged into darkness indicates a fault, possibly one that's the 'wrong' side of the fuse to blow it and protect the car.

What happened when you turned the heater knob away from speed 4?

Your earlier question about the electric dash, if the alternator is on its way out, they yes it'll still run, those dash board don't actually need a lot of power.[/quote]


mmm never thought about it being the heater motor. I didnt get chance to turn it away from 4 as it cut out and i never bothered to jump it afterwards.

Ill try and borrow a voltmeter to check the voltage that should hopefully give an indication if its the alternator

 

[TRXnMe]

mmm never thought about it being the heater motor. I didnt get chance to turn it away from 4 as it cut out and i never bothered to jump it afterwards.

Ill try and borrow a voltmeter to check the voltage that should hopefully give an indication if its the alternator

If it was an immediate loss of electrics when you turned the heater onto 4 then the heater motor cicruit has to be the favourite suspect.

If I misunderstood and the power 'faded out' when you put the heater to 4 then it might not be the culprit, it could just be concidental.

 

[ryanshelton]

Nope didnt fade out just went off. Would this cause the battery to go flat though when the car wasnt in use?

 

[TRXnMe]

Nope didnt fade out just went off. Would this cause the battery to go flat though when the car wasnt in use?

If the heater is in '4' when you park the thing, and it's the live side that's got the short then yes, it might flatten the battery while the car is parked.

 

[ryanshelton]

SWMBO has just said she doesnt have it on 4 very often so that rules that out grrr

 

[TRXnMe]

SWMBO has just said she doesnt have it on 4 very often so that rules that out grrr

Maybe not.....

You either have a fault in the heater circuit, or it fluked it to cut out when you switched to 4.

To lose all electrical power as quickly as you describe I'm expecting you to find a fuse has gone tomorrow, or a wire that was loose / frayed will no longer be completeing the circuit it is part of.

When you get chance tomorrow, if you haven't already found the fault, check the battery voltage with the heater off, then with it on 1, 2 and 3, then pull the fuse and check it again (assuming the fuse didn't blow today).

 

[ryanshelton]

ill borrow a voltmeter tomorrow and check it. Im guessing it should be consistent no matter what the heater is set on if its controlled by a resistor? Will also check the fuses, hoping its something as simple as a fuse but the way my lucks been recently i highly doubt it!

 

[TRXnMe]

The volt meter should indeed read close to the same for each of the working settings, I'd expect it to be very slightly different when the heater blower is off, assuming the engine is running, you'll see a larger difference betwwn off and on with the engine off..

The other thing is to listen to the engine, when you put a big load onto it at tick over you'll hear the difference (think air con, although that's the pump coming in, not the alternator). If the alternator does output more power it will put slightly more load on the engine.

I'm not talking a huge amount of load here, from memory a car with day time running lights fitted (lights on all the time) will use between 0.75% and 1.5% more fuel than a car without day time running lights fitted, so that gives you a clue as to how little power the alternator generally takes.