Battery Dying Over Night - Strange Symptoms

[SECURITY]

my battery keeps going flat and i dont know why. i could leave it over night and the next morning it will barely have any power to turn on. i know its not a dead battery as i had it tested. the alternator keeps the battery charged just fine.

it started happening randomly which has me very confused.

these are the current symptoms..

- the antenna motor keeps trying to pull the antenna down (there is no antenna in there - someone randomly broke it). i cut off the power feed for this and the battery still keeps going flat. the weird thing is the deck doesnt stay on - it turns off. where does the power for the antenna motor come from?

- my AFR gauge stays on after i pull the ignition out. its power feed is connected to the ECU's ignition power feed. i pulled out the power cord for the gauge and it still goes flat.

when i pull the main relay/fuse thing out from next to the battery in the boot, everything turns off and i'd assume the battery wont go flat - i'll report back on this though.

does anyone have any idea on how i can track the issue down? i dont have a multi meter to test anything at the moment though.

any help would be great.

[Got a Pulsar]

Does your boot light go out when you close the boot?

Put your best mate in there to check or pull the bulb out. Maybe???

any help would be great.

Edited June 11, 2011 by Not a Pulsar

[AngryRB]

Im having the same problem at the moment..... actually had this on the skyline and the falcon...

In the case of the falcon i sure it must of been the old speakers in the back that were shot, or the interior bulbs somhow contacting the body, in that case i managed to fix it..

for the skyline i have no idea, so im taking the battery off to get tested.

bloody frustrating

[SECURITY]

i just tried updating the firmware on the ECU and it requires me cycle the ignition on and off. when i switched the key off the ECU didnt switch off. i had to pull out the main fuse as i mention before for it to 'cycle'. i just tried turning the ignition off while the ECU was connected to the laptop and it didnt turn off!

so now i know the ECU doesnt turn off. strange! what feeds power to the ecu? is there a relay i can check in line?

[t_revz]

when i pulled out the harness in my 33 there was 2 relays under glovebox jammed in the corner. i would imagine one is for the ecm and other maybe air con. if you have them too try disconnect or swap them

[blk94r33]

i just tried updating the firmware on the ECU and it requires me cycle the ignition on and off. when i switched the key off the ECU didnt switch off. i had to pull out the main fuse as i mention before for it to 'cycle'. i just tried turning the ignition off while the ECU was connected to the laptop and it didnt turn off!

so now i know the ECU doesnt turn off. strange! what feeds power to the ecu? is there a relay i can check in line?

You haven't modded the over-heat fan to run with the air-con? This was causing the same problem with mine...

[SECURITY]

thanks for the suggestions guys.

i ripped out the aircon system in my car mate.

[Munkyb0y]

afaik the aerial up/down is enabled by the ecu too. so it's all related to your ecu i'd imagine.

You haven't modded the over-heat fan to run with the air-con? This was causing the same problem with mine...

this happened to me too.

[SECURITY]

yeah i suspect the relay feeding power to the ECU is shagged. i might hook up a kill switch connected to the main relay till i work it all out though.

[blk94r33]

thanks for the suggestions guys.

i ripped out the aircon system in my car mate.

Even so, if the relay for the aircon is still there and wired up as mentioned, it can cause this.

[SECURITY]

i havent modded the air con system in any way so i doubt thats the issue. ill check out the relays behind the glove box and see what happens.

i pulled out the main fuse in the boot and it doesnt lose charge. i might just hook it up to a kill switch if i cant find the problem soon.

keep the suggestions coming guys, im willing to try everything.

Edited June 12, 2011 by SECURITY

[t_revz]

i havent modded the air con system in any way so i doubt thats the issue. ill check out the relays behind the glove box and see what happens.

i pulled out the main fuse in the boot and it doesnt lose charge. i might just hook it up to a kill switch if i cant find the problem soon.

keep the suggestions coming guys, im willing to try everything.

those relays i mentioned earlier are behind the ecm facing outwards...but i still dont know if they are for the ecm but would be most likely and worth a try

[75coupe]

does the car have an alarm system in it?

alarms have rechargeable batteries and if that battery has decided to die (which happens quite a bit) the alarm will run off the cars battery instead...

[SECURITY]

it does have an alarm but that doesnt explain why everything stays on. if the alarm was draining the battery then the other things shouldnt be happening regardless.

pulling out the main fuse didnt really do anything, it still went flat. i tried the relays behind the ECU, i swapped them around and nothing happened. im starting to think its the actual ECU.

[SECURITY]

So I may have a little progress. I unplugged the ECCS relay and connected it to another known working one with no success. Although everything turns off when I pull the ECCS relay off.

I then started the car without the ECCS relay connected and it started but stalled around 5-7 seconds after running and everything else switches off when I take the key out. Every time I pull the key out and try start it again it starts and stalls. Does this mean anything to anyone?

[SECURITY]

found the problem. the ECU's pin 16 isnt sending 12v to the ECCS relay when the key is turned off, its constantly grounded.

[SECURITY]

figured it out.

the ECU wasn't sending 12v to the ECCS relay (pin 16) when the ignition is turned off which keeps a lot of accessories on. it was continually grounded. sent the ECU off to get repaired and now its working great.

[SargeRX8]

My car was at the tuner the other day for about a week. The battery died. When they went to jump it they said there was a pretty big spark which indicated that something was drawing alot of current with the car off... Everything is completely off the only thing which looks to be on is the alarm. I'm going to disconnect the sound system when this weather f**ks off.