Ok so here is a really weird one,
I am sure it is something really obvious that i just don't know about,
so, last week i replaced my battery and all was good.
car was running, went for a drive started immediately all was great.
locked her up, threw the cover over it, and she has sat there all week.

now, today i go to do some work to her i can't unlock her with my remote....
so i use the key, open the boot check the battery, it is connected, and it has its green indicator light,
then i go to the drivers door, unlock it with the key, it unlocks but does not unlock the other doors,
i put the key in the ignition and turn it, and get nothing at all.
she is dead.

So checked the voltage and only 1.5v
disconnected the - cable, checked the voltage on the battery and 4.5v
(different reading battery connected v not)

now connecting a new battery to start it.
appears that there may be a drain even tho i never registered one on last test.
And my battery shows full charge in its indicator but it is not.

 

Ok so i connected a spare (smaller battery can’t start with this one)
while i put my battery on charge.

now, i have positive connected to battery, then run my voltmeter from negative battery to car negative terminal to check for drain and i get .28A.
Fun fun fun

 

So,
i have pulled every fuse and still get same reading.
as i was by myself and could not do it one by one,
i unplugged all the fuses from one fuse box, checked the reading, then put them back and moved on to the next one.

 

That .28 amp at 12 volts equates to a 3 to 4 watt drain.
I am suspicious that you have a small bulb turned on somewhere possibly in the boot?
I just located a similar problem in a friends 1956 Rolls Royce.

Did you ever get the alternator low voltage sorted out in your !0 Jan post this year?
Unless you are getting 13.8 to 14.2 volts out your battery will not be getting a full charge.
If you have a crook diode in your alternator that could also be the power drain problem. You could try disconnecting the power out lead

These modern cars also have small residual drains on power for such things as anti-theft and power to the receiver for remote lock/unlock.

I have fitted a battery disconnect to the earth lead my X300 as it might go a couple of weeks without being driven as 3 other Jags, a Falcon ute and Mitsubishi shopping trolley get their turn.

 

Not sure if you saw my last post, but i have just disconnected every fuse and get the same reading.
so i am unsure as to what this drain might be.

i replaced my battery as stated but had not yet got to checking the alternator more.
was planning to test today but well then this happened. And I can’t start the car atm.
at this point all i can suspect is that it is another reason to suspect bad alternator.

i will also look at a battery disconnect as i just started a new job and it came with a ford escape for a daily driver the jag will be the weekend toy now.

 

Actually there is no power draw…..
i realised i had the multimeter connected incorrectly..
connected the way i had it on the vma was giving me milli amp reading.
The .28 i was seeing was not .28 amp. It was way smaller. It us the draw from the multimeter itself.
it reads .28 like this when just connected to a battery alone.

so when i connect the plug to the 10A on the multimeter i get no reading.

so now i have sorted my stupidity,
it leaves me with why the hell has my brand new batter drained over the course of a week?

 

When frustrated is when I connected my battery backwards , twice now

New batteries are junk now

 

i just don’t get it.
unless i am checking for a battery drain Incorrectly there is no measurable drain.

so i have no god damn idea.
my brand new battery is currently on charge.
so lets see what happens after that

 

Ok,

so alternator is working good.
i started the car, disconnected the battery, the car keeps running, connected the voltmeter to the battery connectors and get 14.32V so that is good.

but there is some fluttering on the volt guage and the revs fultter up and down a bit.

connected the battery and the revs dropped a but,
and the voltage dropped to 13.8v


on the plus side, my high idle is non-existant.
idling in p at 8-900 (sometimes flutter up to 950-1000)
and in d it is at 700

 

Ok so please help an idiot here.
i must be doing something wrong…..
as now my battery was 12v.
now after sitting in the car doing nothing for 20mins it is 11.8 v.
there is clearly a battery drain.

what am i doing wrong to not find this?

 

It sounds like the revs should be lower at idle. I believe closer to 750 in neutral and 550-600 in drive.
Something is causing a slightly higher idle rpm maybe a vacuum leak or o2 sensor readings, but I can't think how that could relate to the battery drain.

 

the high idle is an issue i have had for a while and tried many things to rectify.
this is still lower than what it was before.
i am just a bit lost on this battery issue

 

So, i have double checked, triple checked, the reading i am getting is 28 mili amp drain.
which is perfectly normal. Compared with other cars i have here and get same kinda reading also,
so now i really have no idea why the hell my battery is draining.

 

Duff battery. Not all that uncommon sadly. The Green indicator ( a yuasa battery?) doesn’t in my experience seem to be reliable. I have had to return a couple of them, which manage to fool my battery charger and conditioner into thinking they are charged, but they wilt when connected to the car.

 

Have the battery sitting out of my car and it is holding charge atm.
only drops charge when connected to car.
that has me thinking not the battery.
but hey, i mean i have no idea what else

 

one thing i have noticed is every time i reconnect the battery my antenna raises, then after about a minute it lowers.
is this normal?

 

I have never seen the antenna raise when reconnecting the battery. Could it be that something on that circuit is staying active, possibly causing the power drain?
The sounds system, cd player or antenna might be worth disconnecting to see if it makes a difference.

 

On the line of the antenna there are 2 or 3 fuses X , Y , and Z for the stereo system

The stereo head controls the antenna.

The antenna motor.specific fuse is # 8 trunk fuse box which is hot at all times bypassing the trunk fuse box king relay in the corner of the box

To raise the antenna B + is applied to the pin 5 ( Light Green / Black wire ) on the stereo head connector on the car side ( this is only a controlling input to a relay inside the antenna motor assembly )

To lower the antenna the pin 5 is grounded , your case it may have found a ground somewhere as a fault

 

So i suspect it is the antenna itself for a few reasons.

this was not happening until recently and i installed the stereo quite some time ago.

i just recently “repaired” the antenna

and it does go down after about a minute once it rises.
so it appears to be grounding out when battery is connected, and then dropping when it gets no radio signal.

 

You can remove the fuse when extended.

if the drain still accures you have an issue with the Light Green / Black wire