Parasitic drain

[e30-wheels]

Parasitic Drain 325 e30

Over the last couple of years my battery when connected goes flat after about two week of not starting the car, finally got round to try and find the problem.
I'm getting a drain of 90.20mA done all the fuse meter checks and  isolating of various components to no avail except for fues 21, although i was not having a problem with the instrument cluster i disconnected the blue plug and the 90ma drain reduced to 2.2mA.(Central locking) checked the batteries which were low and had them replaced,  reconnected  the cluster now i'm getting a drain of 70.2mA removing the fuse for central locking lowers the drain to 68mA, if im correct im looking for 35 to 40 mA dont know what else to check help badly needed
Many thanks in advance

[Contours]

Maybe you have an accessory or something connected directly to the battery and not going through the fusebox.

[paultv]

Do you have an alarm system? Or even the remains of one? You don't say if you've got an audio system...

It's not enough current for a bulb, except electric window switch lamps which pull 60mA each.

Paul

[e30-wheels]

Maybe you have an accessory or something connected directly to the battery and not going through the fusebox.

I have no accessorys on the car only what it was built with like the radio which i disconnected along with the antenna, it all seems to be leading back to the instrument cluster and that along with the service indicator works fine. Thanks for your input

[e30-wheels]

Do you have an alarm system? Or even the remains of one? You don't say if you've got an audio system...

It's not enough current for a bulb, except electric window switch lamps which pull 60mA each.

Paul

Hello Paul
I don't have an alarm system or any related wiring,  the audio system is the original Becker Mexico fitted by BMW when i got the car new, this was disconnected  when doing tests, all the bulbs in the window switches are U/S I have now go new bulbs another job as and when, all seems to go back to the cluster  SI board, i will swap this as i have a spare with good batteries. Many thanks

[biffer]

I had a 60ma drain ,which i tracked down to the instrument blue connector/SI board- removing the board ( which had already had the batteries replaced) reduced the drain to a more normal 25ma.
Taking a chance on a second-hand board from Ebay cured it.

[Blanca]

Sorry, batteries in the instrument cluster? I have had mine apart (to repair speedo gears) and a bulb problem but didn't see any batteries!

1987 E30 320i saloon

My battery last about 10 days to a fortnight unused and I mean dead flat, takes two days on a 0 .5A charger to recharge, lucky I keep a starter booster in the boot.

[paultv]

Sounds like your glove box light is not switching off!

Paul

[paultv]

Fuse 21 feeds:

Boot/trunk light
Radio
Chime module
Instrument cluster
Active Check control
Dome light
Self Charging Flashlight in Glove box

Paul

[e30-wheels]

Sorry, batteries in the instrument cluster? I have had mine apart (to repair speedo gears) and a bulb problem but didn't see any batteries!

1987 E30 320i saloon

My battery last about 10 days to a fortnight unused and I mean dead flat, takes two days on a 0 .5A charger to recharge, lucky I keep a starter booster in the boot.

Did you remove the SI board from the cluster housing you need to to see the batteries. also if you have not aready done it do a parasitic drain test on the car battery.

[e30-wheels]

Sounds like your glove box light is not switching off!

Paul

Hello Paul
For testing a disconnected the glove box light,boot light

[e30-wheels]

Fuse 21 feeds:

Boot/trunk light
Radio
Chime module
Instrument cluster
Active Check control
Dome light
Self Charging Flashlight in Glove box

Paul

Hello Paul
All the above as listed have been isolated for testing except the chime module ( dont have one) test 2.2 mA, reconnected test 70.2 mA isolate cluster test 2.2mA unless there is something else on that circuit that i dont know about im thinking it must be a fault in the cluster even though it works perfectly.

[paultv]

I'm going to measure mine.... all off current drain that is !!!

Paul

[e30-wheels]

I'm going to measure mine.... all off current drain that is !!!

Paul

Yes thats it, when i did mine i took all the fuses out first then did a test and got zero mA then put the fuses back one at a time but left fuse 21 out testing as i went noting the reading of any fuse that showed any mA,

[onthames]

Sounds like your si board batteries are on the way out.

[e30-wheels]

Sounds like your si board batteries are on the way out.

New batteries fitted Monday this week, i think it may be another fault on the si board
Thanks anyway

[fixedwheelnut]

It sounds like it may be your cluster as you say you have replaced the SI Board batteries, hopefully with like for like Ni-Cads

Another drain can be the door switches faulty, the front ones switch courtesy lights but also earth out the relief relay that allows you to power up the electric windows with the front doors open. Mine had a sporadic drain and I noticed the electric window switches illuminated sometimes with all the doors shut. Two new door switches fixed it

[e30-wheels]

It sounds like it may be your cluster as you say you have replaced the SI Board batteries, hopefully with like for like Ni-Cads

Another drain can be the door switches faulty, the front ones switch courtesy lights but also earth out the relief relay that allows you to power up the electric windows with the front doors open. Mine had a sporadic drain and I noticed the electric window switches illuminated sometimes with all the doors shut. Two new door switches fixed it

The old si board batteries were replaced as near as possibile like for like same rating but slightly fatter by a local electronics repair company i assume they were original as dated 1989 one was u/s the other 2.6 volts, before new batteries battery drain was over 90mA after 70.2mA both before and now the cluster works perfectly, the window switch light bulbs are all u/s and have been removed pending the fitting of new bulbs, you mention a relief relay i can' find a relay on my window circuit only a circuit breaker and number 17 fuse which was removed when testing do you know its location. I have another si board with good batteries which i will fit today, fingers crossed.
Many thanks for your reply

[e30-wheels]

Problem solved, I fitted my spare si board but the rev counter and fuel econ gauges did not function then realised i had left 21 fuse and a relay out refitted them and all was ok with all systems now working perfectly, checkd the parasitic drain now reading 7.2mA, so the problem ended up being a fault somewhere on the old si board.
Hopefully no more flat btatteries.

Thanks to all for the help and suggestions.

[martauto]

Problem solved, I fitted my spare si board but the rev counter and fuel econ gauges did not function then realised i had left 21 fuse and a relay out refitted them and all was ok with all systems now working perfectly, checkd the parasitic drain now reading 7.2mA, so the problem ended up being a fault somewhere on the old si board.
Hopefully no more flat btatteries.

Thanks to all for the help and suggestions.

Great news mate !!!!
I would not have thought about this in a million years

Mart.

[e30-wheels]

Problem solved, I fitted my spare si board but the rev counter and fuel econ gauges did not function then realised i had left 21 fuse and a relay out refitted them and all was ok with all systems now working perfectly, checkd the parasitic drain now reading 7.2mA, so the problem ended up being a fault somewhere on the old si board.
Hopefully no more flat btatteries.

Thanks to all for the help and suggestions.

Great news mate !!!!
I would not have thought about this in a million years

Mart.

Thanks Fixedwheelnut was a great help.

[Blanca]

Being a bit paranoid I checked my batteries and the CR14250 SE 3v Lithium batteries are 2.6v after sitting with no main battery in the car for over a month. Everything on the cluster works just fine but I am getting battery drain, about ten days and it's flat but driven every few days it is fine and starts first turn.
Would this be OK as I don't really want to mess about changing perfectly good batteries.

[e30-wheels]

Being a bit paranoid I checked my batteries and the CR14250 SE 3v Lithium batteries are 2.6v after sitting with no main battery in the car for over a month. Everything on the cluster works just fine but I am getting battery drain, about ten days and it's flat but driven every few days it is fine and starts first turn.
Would this be OK as I don't really want to mess about changing perfectly good batteries.

When my batteries were replaced one was zero volts the other was 2.6v apparently 2.6 volts is flat, like you my instruments all worked ok although i had to reset the service lights each time the main car battery was low, apparently bad si board batteries can cause a high parasitic drain on the system , I would certainly replace the si batteries, when new the batteries are about 3.3 volt. pull the blue plug off the cluster and see what readings you get.

[Blanca]

Two new batteries on the way,

https://www.ebay.es/itm/283281016145

Put it all back for now as with the wheel off it is not too bad a job, (unless you drop the thumb nut off the dash cover down the inside of the consul )

[onthames]

Being a bit paranoid I checked my batteries and the CR14250 SE 3v Lithium batteries are 2.6v after sitting with no main battery in the car for over a month. Everything on the cluster works just fine but I am getting battery drain, about ten days and it's flat but driven every few days it is fine and starts first turn.
Would this be OK as I don't really want to mess about changing perfectly good batteries.

When my batteries were replaced one was zero volts the other was 2.6v apparently 2.6 volts is flat, like you my instruments all worked ok although i had to reset the service lights each time the main car battery was low, apparently bad si board batteries can cause a high parasitic drain on the system , I would certainly replace the si batteries, when new the batteries are about 3.3 volt. pull the blue plug off the cluster and see what readings you get.

I think it drains the battery cos your car is trying to charge up those fucked si batteries.

[e30-wheels]

Being a bit paranoid I checked my batteries and the CR14250 SE 3v Lithium batteries are 2.6v after sitting with no main battery in the car for over a month. Everything on the cluster works just fine but I am getting battery drain, about ten days and it's flat but driven every few days it is fine and starts first turn.
Would this be OK as I don't really want to mess about changing perfectly good batteries.

When my batteries were replaced one was zero volts the other was 2.6v apparently 2.6 volts is flat, like you my instruments all worked ok although i had to reset the service lights each time the main car battery was low, apparently bad si board batteries can cause a high parasitic drain on the system , I would certainly replace the si batteries, when new the batteries are about 3.3 volt. pull the blue plug off the cluster and see what readings you get.

I think it drains the battery cos your car is trying to charge up those fucked si batteries.

Yep thats normally it, in my case although it did reduce the drain a bit there was another unknown fault in the si board. Your car looks the same as mine 1985 4 door, white
but i have bbs wheels, i have a set of wheels same as yours with new tyres on they were reconditiond about 5 years ago and never used, i was about to put them on e bay just thought i would mention it, if and when you get to sort your si board i my have spare you can borrow to check against yours also somone that can supply and fit batteries for £28.00, im in Battle nr Hastings.
Cheers

[Blanca]

I like the 'bottle top' wheels rather than the BBS, and easier to clean too, I have total of 7 of them.

[e30-wheels]

Parasitic Drain 325 e30

Over the last couple of years my battery when connected goes flat after about two week of not starting the car, finally got round to try and find the problem.
I'm getting a drain of 90.20mA done all the fuse meter checks and  isolating of various components to no avail except for fues 21, although i was not having a problem with the instrument cluster i disconnected the blue plug and the 90ma drain reduced to 2.2mA.(Central locking) checked the batteries which were low and had them replaced,  reconnected  the cluster now i'm getting a drain of 70.2mA removing the fuse for central locking lowers the drain to 68mA, if im correct im looking for 35 to 40 mA dont know what else to check help badly needed
Many thanks in advance

Update on Parastic drain

Car has not been started for about 10days, i started it today it was just like having a new battery it looks like problem has been sorted.

[Blanca]

Just fitted a new pair of batteries to the instruments, very easy job and I even remembered to move the jumper over and back when doing it. Lets hope tat helps with battery drain, will soon see.

[e30-wheels]

Just fitted a new pair of batteries to the instruments, very easy job and I even remembered to move the jumper over and back when doing it. Lets hope tat helps with battery drain, will soon see.

I have my fingers crossed for you.

[Blanca]

First trip out yesterday and all seemed OK until I looked at the vac' meter, it wasn't working and the tacho was bouncing about 100rpm, so need to check that out.

[e30-wheels]

First trip out yesterday and all seemed OK until I looked at the vac' meter, it wasn't working and the tacho was bouncing about 100rpm, so need to check that out.

Could be a dry jointon the battery soldering, the electronics engineer told me when he did mine you have to use the correct solder and flux because the tabs on the batteries are stainless steel the flux is an acid flux the solder is one with a silver content in it.

[Blanca]

First trip out yesterday and all seemed OK until I looked at the vac' meter, it wasn't working and the tacho was bouncing about 100rpm, so need to check that out.

Could be a dry joint on the battery soldering, the electronics engineer told me when he did mine you have to use the correct solder and flux because the tabs on the batteries are stainless steel the flux is an acid flux the solder is one with a silver content in it.

I don't think that's the problem as these FDK batteries came with the tabs tinned, not bare stainless.

[e30-wheels]

First trip out yesterday and all seemed OK until I looked at the vac' meter, it wasn't working and the tacho was bouncing about 100rpm, so need to check that out.

Could be a dry jointon the battery soldering, the electronics engineer told me when he did mine you have to use the correct solder and flux because the tabs on the batteries are stainless steel the flux is an acid flux the solder is one with a silver content in it.

I don' think that's the problem as these FDK batteries came with the tabs tinned, not bare stainless.

Like mine and before you replaced the batteries did you say in an earlier quote that the tacho and vac meter were working, just a thourght you have got the neg and pos correct on the new batteries, i did read somewhere that some batteries the tabs are fitted diffently and you have modify for the neg and pos to be correct to the board.

[Blanca]

Batteries have two + pins and one neg pin, cannot fit wrong.

Everything worked just fine before.