Flat battery but why?

[Fossil]

I've bought a brand new battery but went to start it today and it's flat. Something is draining my battery very quick. I haven't had it going for a few days. All I connected to it was a in car dash style tv stereo. One of those cheapie of ebay. However, there is some kind of box connected to the positive and running somewhere. It does have a rear air conditioner that I don't want. Could this be powering that? Could somebody please tell me what should be connected from my positive and negative terminals. I just want it stock standard. Any ideas how I can take it back to that please? Here is a connection similar to mine. What's that black box connected to the positive terminal with the thick red wire for as I have one as well? I just want stock standard so can I get rid of this box?

[Umai Naa!!]

That box looks standard. I'd probably leave it as is.

Perhaps unplug the new stereo and see if that's what's causing it. You need to be very sure you've wired it up correctly, because IGN OFF, is not IGN OFF until you pull the key out.

[Gold Coaster]

Not sure what's what there but if you have a multimeter you might be able to trace the drain. There's lots of help on Youtube such as How To Perform a Parasitic Draw Test - EricTheCarGuy - YouTube

[Fossil]

That box looks standard. I'd probably leave it as is.

Perhaps unplug the new stereo and see if that's what's causing it. You need to be very sure you've wired it up correctly, because IGN OFF, is not IGN OFF until you pull the key out.

thanks. I was working in it today and had the key in the ignition all day. I did turn off the interior lights but that was all. Still don't understand what that black box is for though?

[Umai Naa!!]

If you pop the cover off, it'll be full of fusible links to everything in the van.

[Fossil]

If you pop the cover off, it'll be full of fusible links to everything in the van.

any ideas on what they may be though?

[Umai Naa!!]

Usually for things like the fans, alternator, that sort of thing.

[Fossil]

Usually for things like the fans, alternator, that sort of thing.

Okay. I'll havet to jumpstart it in the morning and take it for a drive. An hour should bring it back up to full charge I reckon. Any precautions when jumpstarting I need to know about as I'm very new to veedub? I appreciate all your help. I will get a multimeter on Thursday and do some tests to see what the big drains are.

[Sunny43.5]

AS Umai says the stereo could be the culprit , I have found some of those on Ebay have wiring which is all over the place .Many years ago I had to unplug several wires from the supplied connector because they were in the wrong holes . The diagram in the booklet said one thing and the label on the back of the unit had it another way . What year van ?

[Fossil]

AS Umai says the stereo could be the culprit , I have found some of those on Ebay have wiring which is all over the place .Many years ago I had to unplug several wires from the supplied connector because they were in the wrong holes . The diagram in the booklet said one thing and the label on the back of the unit had it another way . What year van ?

It's a 2002 T4 2.5 TDI

[Sunny43.5]

Ok now if my memory serves me well there was an issue with aftermarket radios causing havoc with the electrics due to a wiring issue , seems that some of the head units could cause someone using a diagnostic tool to end up with the stereo actually shorting out the diagnostic tool and wrecking the tool . Now I am not sure if it would cause a flat battery though seems a bit odd , now silly question did you fit an external amplifier at the same time , the reason to ask was there are some amps which use a strange system to turn them on and off . Most use a "Pcon "wire but others use a pulse via the RCA cables and if you select that without a matching head unit the amp will stay on even after the radio and ignition is switched off . Did this on a friends Honda took us a
trip back top the auto shop to find the switch to change .

[weonarok]

Flat battery but why?

I'd be unplugging the head unit first to see if that rectifies your issue.

I have read where Amarok owners have had flat batteries after fitting cheap head units, even with the key removed. The problem is that they are designed to go Into a light sleep mode for a period (around 1/2 hour or so) so that if you were to return to your vehicle within this time the head unit should start up quickly and not need to reboot which can take over 20 seconds with some units. The fault was that they didn't fully turn off after this 1/2 to 1 hour of sleep mode and would continually place a drain on the battery rendering a flat battery overnight.

By the way, a battery that has been drained below 10v will have a very shortened life span and in some cases could actually wreck it completely. An hours drive may be enough to be able to top up the battery to start the vehicle but it would take a minimum of three hours to get to 100% SOC. A overnight trickle charger is the way to go which can be scored for as low as $20-30, but if you can afford it a 5 or 7 stage charger can be had for $100-150.




Cheers dave

[Transporter]

I'd be unplugging the head unit first to see if that rectifies your issue.

I have read where Amarok owners have had flat batteries after fitting cheap head units, even with the key removed. The problem is that they are designed to go Into a light sleep mode for a period (around 1/2 hour or so) so that if you were to return to your vehicle within this time the head unit should start up quickly and not need to reboot which can take over 20 seconds with some units. The fault was that they didn't fully turn off after this 1/2 to 1 hour of sleep mode and would continually place a drain on the battery rendering a flat battery overnight.

By the way, a battery that has been drained below 10v will have a very shortened life span and in some cases could actually wreck it completely. An hours drive may be enough to be able to top up the battery to start the vehicle but it would take a minimum of three hours to get to 100% SOC. A overnight trickle charger is the way to go which can be scored for as low as $20-30, but if you can afford it a 5 or 7 stage charger can be had for $100-150.




Cheers dave

The trickle charger is just what the name says, it trickle charges the battery and nowhere on earth will fully charge a flat battery in the T4 or any other van. Especially if there might be an electrical fault and the battery is constantly drained.

You could even struggle to put enough charge in it to start in the morning.

[weonarok]

The trickle charger is just what the name says, it trickle charges the battery and nowhere on earth will fully charge a flat battery in the T4 or any other van. Especially if there might be an electrical fault and the battery is constantly drained.

You could even struggle to put enough charge in it to start in the morning.

I was not indicating to trickle charge the battery while the fault was still present.

You have cured me, I will now refrain from touching the keyboard, read only. [emoji85][emoji87][emoji86]




Cheers dave

[The_Hawk]

I'd highly recommend the CTEK range of chargers, I've been using one for a few years on my Golf to top off the battery (especially in winter) when I know I'm not driving enough to charge the battery.

These units are designed to charge while all connected to the vehicle so I wouldn't think there would be an issue of charging while the drain problem is still present, sure if it's a huge drain it still wont charge the battery, but I can't imagine it's actually that bad.