2003 406 hdi(110) estate flat battery everyday help need to

[macx86]

the car done a week with out going flat went to go out yesterday and it was flat. when the battery is taken off the terminal when i park it up, then re connect it in the morning.it starts 1st time.

[Gary406]

is it a screw top positive terminal ?

ive found on my car it more or less always shorts and cracks if you touch the top of it.

might be worth changing the screw top that clips to the battery positive side

thats of course it is the screw top type.

[macx86]

it not a screw top positive terminal. if the battery flat and i jump start it with jump leads after 15 min drive the battery can start the car for the rest of the day

[Gary406]

you need to do what steve said. multi meter on battery check voltage. start pulling fuses from fuse box 1 by 1. have sum watch the multimeter.

and once the defending fuse is pulled you will know which circuit to look.

thats the easiest and best way probably.. multimeters are cheap nowadays from maplin..

[lecky4]

If you test the battery voltage it will show 12V. Even removing the fuses 1 by 1 will show 12V no matter whats on as thats the battery voltage. Removing the fuses 1 by 1will only show you anything if you're measuring the current drawn. Be carefull if you go down this route as car batteries hold quite a punch, for instance if you try to start the car you'll blow the average mutimeter, most of which will only handle up to 10 Amp's so there's plenty of systems which draw to much anyway.

[steve_earwig]

It needs to be amps, you could do it with volts but the whole procedure would take several weeks... So long as it's fused it'll be ok. I can't think that the draw will be more than (or anything like) 10 amps, however I have worries that disconnecting and then reconnecting the battery will have all sorts of things charging up and blowing the fuse, so what it really needs is the ammeter put into series with the battery without disconnecting it. Unless you have access to a clamp meter of course.

Mpre stuff to worry about here: viewtopic.php?f=10&t=13431

[lecky4]

Steve, you just can't do it measureing volts you'll only be measureing the battery voltage. There should be no problems connecting a multimeter set to Amp's in series. As for the 10 Amp's there's more than 1 or 2 fuses of 25 or 30 Amp rating on the 406 and how do you connect an Ampmeter without disconnecting?

[lecky4]

To be honest if you want to see if you have a permanently live circuit this is the safest method.
1) Disconnect the battery earth.
2) Set your millimetre to Ohms.
3) Connect the black lead to a good earth, i.e. the actual battery earth cable.
4) Individually remove each fuse one at a time and check for continuity to earth.

Make a note of all the readings you get so you can look back after and spot something that wasn't so obvious at the time.

[steve_earwig]

Steve, you just can't do it measuring volts you'll only be measuring the battery voltage.

Yeah you can, it'd be pretty pointless 'cos it would take hours for any change to be obvious so it would take weeks (yes, I was being silly)

As for the 10 Amp's there's more than 1 or 2 fuses of 25 or 30 Amp rating on the 406

But hopefully none of that's going to be happening because the car's meant to be turned off and at rest.

and how do you connect an Ammeter without disconnecting?

Find some domestic wire (1.0 or 2.5mm), strip off a fair bit of one end and wind it around the battery terminal post, fold it back on itself and twist it so it's tight around the terminal. To the other end connect one lead of your ammeter and the other lead connect to the battery connector. Remove battery connector.

Edit: The trouble is there's a lot of electronics on these cars and a lot of it is always live, e.g. the airbag ecu which is trying to charge itself up in case the battery is disconnected in an accident. Whenever I have my battery disconnected there's always a small spark as I connect it.

[lecky4]

1) If a battery shows less than 12V it's got knackerd cells, they should show 12v even when flat. The charge is the available Amp's.

2)If you think you have a live cicuit you suspect not everything is off even if it should be which is why you'd be doing this check.

3)You've still disconnected but in a very clever way to avoid the spark. Like it.

That spark means there is a circuit made but like you said it's a complicated car. I have had it with mine but not every time for some reason.

[macx86]

have not had time to get out to work on car with a 4 year old son and 6 months old girl. been going throw his toy for a car boot so he can sell them to spend the money on what he would like. i started making my sump for my salt water aquarium. the car been park up for 4 hours or so and i went out to put the car boot items in the car boot i notice the sat nav unit had an orange light on. is it this light that flat that battery over time. i think that light should go out. could people with sat nav have a look to see if the light turn off or dose it come on when you unlock the car i have no disc for it sor it just dead wait (thinking of taking the sat nav unit out)

[macx86]

since it been warmer and dry the car been fine so i think that the damp or water geting onto so wires and killing the battery