Electrical advice needed

[11redrex]

Electrical advice needed for my peugeot. Can anyone explain to me in idiot terms how to check for a battery drain ?

Story first : The battery was flat on monday, so I bump started it and drove it to work (80 miles) It was ok midday, but flat again in the evening. Got a jump start, drove it home, and and used the maverick for two days. Put a new battery on it wednesday night, fired up fine thursday morning and thursday lunchtime, but thursday evening it was flat again. Bump started it friday morning, disconnected the battery when I got to work and it was fine friday night.
Saturday revealed a broken mounting bolt on the power steering pump which had taken all the tension off the power steering/alternator belt. Fixed that, took it out for a run to charge it. Started fine later on Saturday, wouldn't start this morning though, wouldn't even take a jump start off the Maverick. Totally and utterly flat. Story over.

Got it on charge now, the charger is showing 12.5 volts and half charged.

I think something may be draining the power. So, ignition off, negative lead disconnected, volt meter between the negative lead and the negative battery terminal showed just under 12 volts before I started charging it.
Is that right or do I need a resistor to check for a voltage drain ? I've seen a video and he had a resistor. Unplugged each fuse while checking the meter and no change anywhere. :nenau:nenau:nenau


Or.... does it just need charging up properly ? Bearing in mind the new battery was fitted before the belt problem was sorted out, and I hadn't given it much of a run after sorting the belt out.

Got to go to Oxford for 3 days tomorrow. Two spare batteries, jump start pack (useless) and jump leads in the boot !

 

[clivvy]

how old is the battery? Could it just be a duff battery?

 

[briggie]

check the output from the alternator :thumb2

 

[11redrex]

Battery is brand new. Volts across the battery with engine running were around 14. Done all the checks I know how to.

I really just need to know how to check for a drain.

 

[briggie]

It should be done with Digital Volt Meter set on the amps scale and connected in series on the battery negative. You should not have more than 0.03 Amps parasitic drain

To check for a drain shut all the doors and wait for the interior lights to go out and see what the amps reading is this will tell you if anything is draining the battery.To narrow down which circuit is draining you will need to start removing fuses one by one to see if the reading changes.

 

[briggie]

You will need to disconnect the negative terminal from the battery and then put one terminal from the DVM to the negative lead and the other terminal from the DVM to battery negative terminal.

BEFORE you do this make sure the meter is on the amps setting and on the 10A scale and do not attempt to start the engine or you will destroy your meter.

 

[11redrex]

no parasitic drain at all. tried it on all sorts of settings just to check. nothing. no drain. I would have thought I'd see something, even it was very minimal ?
Anyway screw it, battery's disconnected, gotta be up at 3.30 so I'm off to bed now.

 

[briggie]

no parasitic drain at all. tried it on all sorts of settings just to check. nothing. no drain. I would have thought I'd see something, even it was very minimal ?
Anyway screw it, battery's disconnected, gotta be up at 3.30 so I'm off to bed now.

its possible you have a cell down on your battery then ( even though its fairly new ) which acts like a drain on your battery ..... unlikely , but possible

 

[briggie]

just had a thought ( im sad arent i ? ) ..... another possibility is you have a fault with the alarm/immobilisor ( if it has one )

 

[11redrex]

Its not fairly new briggie mate, it's brand new. I'm definitely going to bed now....

 

[melissachels]

Check ur alternator belt is tight enough! I had the same problem, tho mine now has my old 406's battery in it cos I thought a dead cell, but done the same till the belt got tightened properly n runs great now

 

[dollywobbler]

Is the battery definitely flat? Do any lights come on? I'd suspect an electrical gremlin first of all, especially with a modern Peugeot.

It would take a big drain to lose the power during a working day. You'd need to leave something like the interior light on to do that.

You won't see any voltage difference between neg terminal and battery even if there is a drain. As said above, it's the amps that make the difference.

 

[briggie]

Is the battery definitely flat? Do any lights come on? I'd suspect an electrical gremlin first of all, especially with a modern Peugeot.

It would take a big drain to lose the power during a working day. You'd need to leave something like the interior light on to do that.

You won't see any voltage difference between neg terminal and battery even if there is a drain. As said above, it's the amps that make the difference.

yup thats why i asked him to to that :thumb2

 

[(RIP) PLANK]

You will need to disconnect the negative terminal from the battery and then put one terminal from the DVM to the negative lead and the other terminal from the DVM to battery negative terminal.

BEFORE you do this make sure the meter is on the amps setting and on the 10A scale and do not attempt to start the engine or you will destroy your meter.

spot on :thumb2

also test your battery voltage, then start the engine and test it again - in simple terms - it should be higher with the engine running, then you know your charging circuit / alternator is working.

 

[11redrex]

done all the above. No amp drain, volts 12+ / 14+ . The belt which runs the alternator and power steering is self tensioning. I am now thinking the old battery is dead, even though it shows just under 12v on the dvm, and the new battery is faulty - the condition indicator shows knackered even though it says 12v+ on the dvm) dunno.
Had it disconnected all day today and it was fine tonight (of course). Think I'll just do that, its easier than jump starting everyday !

 

[rustic]

When you measured the current drain using the meter, did you set the selector to the 10 amp range AND put the test leads in their correct sockets?:nenau

On most meters you have to move one lead.

If you do find a drain, say several amps, then disconnect the plug from the alternator, as a faulty diode in the diode block in the alternator can drain the battery over night.

 

[11redrex]

will try that tomorrow , thanks rustic. Yup, had the plugs in the right sockets

 

[andrewk]

11redex,

Just to make sure I understand correctly ..........

Story first : The battery was flat on monday

How do you know that the battery was flat? Was it just that you couldn't turn the engine over - or did you check the voltage across the battery?

If it will not turn the engine over, then switch on your headlights and try to turn it over again. If the headlights do not go out fully when you turn the key, the starter motor is not drawing (much) current so you have a bad contact somewhere. Check the cable to the starter motor and its connection. Follow the heavy ground/earth cable from the battery and check the connection to the engine block.

If the headlights do go out then the starter motor is drawing current, but not enough to turn the engine over (coz the battery is probably flat). If the engine were running and the battery was pretty much fully charged, you would expect about 13.8V across it. If the engine has not been not running (and you have not just tried to start it) you would expect about 12.7V across it. If it measures less than 12V when not on charge, then it's flat or goosed.

It was ok midday, but flat again in the evening. Got a jump start, drove it home, and and used the maverick for two days. Put a new battery on it wednesday night, fired up fine thursday morning and thursday lunchtime, but thursday evening it was flat again. Bump started it friday morning, disconnected the battery when I got to work and it was fine friday night.

This kind of odd behaviour suggests that there might well be a bad/loose contact somewhere.

Started fine later on Saturday, wouldn't start this morning though, wouldn't even take a jump start off the Maverick. Totally and utterly flat.

Same question - how do you know that the battery was actually flat?

Andrew

 

[andrewk]

If you cannot turn over the Pug engine using jump leads from a (fully charged) Mav battery, it strongly suggests a bad contact on the Pug somewhere between battery +ve, starter, engine block, earth strap back to battery neg. Again, you can confirm that by switching on the Pug headlights and trying to jump start it. If the headlights don't extinguish/dim when you turn the key then it has to be a bad/loose contact (or less-likely but possible - a goosed starter motor).

Andrew

 

[kitchenman]

Check your alternator, the control circuit may be unwell.

As the battery does not run down disconnected there must be a drain somewhere

Take the wire/s off the alternator with battery connected, if you get a spark you are on your way to fixing it. Should be no voltage there until the alternator starts charging

Thats the thin wires not the main one