I would be grateful of some guidance/advice,my car has a parasitic drain,when left ovenight the battery is too low to start the engine,I discovered this fault after charging the original battery and after checking that radio,interior lights had gone off/sleep the next day the battery was flat,Just obtained a new calcium battery today and did some tests,I am a full time carer so I could not do all I would like today and I forgot to test with lights on and fans running to check alternator properly,

Battery charge 12.9v

engine tickover running 14.2v

This test I have seen on utoob,disconnect negative battery lead,with multimeter set to 10amps (red probe to 10amp socket)bridge the gap between negative battery lead and negative battery post

I understand that the car will be 'awake' whilst doing these tests so would drain more power..

This gave reading of 15.2amps  !!  luckily I know that 15 is bigger than 10 and even though the probes were only on for max two seconds the wires had become quite warm which leads me to believe the reading was correct.

I disconnected both cables on the alternator and got a reading of 16.2 !!! and again was quick removing the probes and they were warm again.

Does anyone know what amps the car draws when switched on/radiobluetooth etc but engine not running.

I have some experience with cars/motorbikes not much with auto electrics.

 

 

 

Marty

This must be something that draws a lot of power ie glow plug relay coming on or a combination of low power faults,bad earth/earths..has anyone any thoughts on this please.

Thanks

Marty

You have to wait for the car to shutdown before performing the parasitic drain test.  Won't work while all the modules are still awake.

Start with the multimeter on a higher setting, and turn it down until you get a reading, rather than starting with 10a setting.

Thanks Tom I think 10a is the highest setting on my meter,yes I understand that the car needs to enter sleep before the test but does the car draw that much normally when everything is awake?

And the draw was higher with the alternator disconnected? I did this to see if there was any drain from the alternator.

Thanks

Not the same generation of car but by way of a comparison mine draws about 8 Amps with the ignition on or immediately after switching off. It then gradually starts to draw a lot less with the ignition off. I would expect a MK4 to draw more current than a MK2.

The only time I have seen figures like yours is with Stop/Start active with the lights, heating and all the S'S extras active.

Might be an idea to pull the fuses for the heated windows, seats etc to see if one of them is staying active.

Maybe disconnecting the Alternator woke something else up and the problem is elsewhere.  

Thanks Tizer,I may have to splash out for a clamp meter as reading around the boards it seems the way to go,Pulling those fuses you mentioned is my next move weather permitting...this is my first 'modern' car if you will,had to retire my 02 mondeo estate ghia and I miss it already..

Thanks again

Marty

Just reading some stuff about amps...I think I was measuring ac amps as my meter has only that function no dc current function,can someone confirm this is the case,I want to learn this stuff as well as sort out the car.

Would this give the high reading?

thanks

I forgot to say the ignition was off when I got the high reading...

I struggle to understand some things at first,I have some issues with learning  but I will understand it more as I work on the car.

🏎️

I don't know what meter you were using and whether you were using it correctly but if it was working properly before it may not be now if it has been overloaded.

You can buy a Clamp Meter quite cheaply that will measure DC Current from Milliamps to 100 Amps. It is a lot more convenient and quicker to use and will be accurate enough for the purpose that you need it for. It is not worth spending a lot of money on a professional one.

With the one I have it tells you on the screen if you have it on AC or DC Current and you need to flick the button to change it to DC.  

4 hours ago, Marty... said:

I forgot to say the ignition was off when I got the high reading...

I struggle to understand some things at first,I have some issues with learning  but I will understand it more as I work on the car.

🏎️

Sorry, I misread earlier.  Thought you had the ignition on, glow plugs pull about 8 amps or so which would explain the high reading.

As Tizer suggests, I think you'd be better off with a clamp meter.

Thanks a bunch chaps 👍

I should have the clamp meter by weekend and will report back,thanks again much appreciated

 

I have made a mistake,the clamp meter I bought does not have mA scale,the reading is between 00.01 and 00.12 on the negative lead,car double locked and bonnet open sensor fooled and left for 2 hours the display shut down in 10 mins nothing visible was active but the battery lost 1 volt in 4hours,forgot to pull the windscreen fuses etc.

I put the code into the radio and it was switched off during test

What could use that much power whilst switched off?

Anyone experienced such  high draw?

Thanks

Hello again 😁

I took some readings from the alternator today

Battery diconnected... 12.6v

Car on tickover ...12.6v

With fan on full and high beams and radio on and on tickover...12.55v

Does this seem ok

Thanks

 

I would like to be able to help myself but I need some help to do that... please, I have little money and cannot afford a garage right now.

Thanks

Marty

Hello I have just inspected the gem/fuse assembly and found corrosion due to the water ingress problem,is it possible to split this case open?

I have a competent workshop and can set up an earth/wriststrap for any sensitive chips in there.

If not is is possible to replace the whole assembly..

Thanks

You can split it open and attempt repair but most people just replace with another one.  You do need to make sure it's got the same number as yours, as they are different depending on trim level etc.

Thanks Tom 👍

I  have removed two screws but it seems held together with hot moulded pins any thoughts on getting it apart?

 

Looking at those corroded pins, you also need to look at the plug and consider changing that also.               On the matter of a suitable clamp meter, I'd be very interesting on knowing where I can buy one that is sensitive enough to measure dc current from mA to amps, as was suggested by Tizer further up this thread... 🤔 

Finally, I'd recommend just disconnecting the negative battery lead at night.. reading threads on different sites regarding parasitic draw, they always seem to occur in Jan/Feb, and hardly get resolved, although one I've read said the auto electrician diagnosed a door lock module, and that fixed it.      Anyway, good luck, and please get back on here with any update, cheers! 

@nicam49, The one I have is a UNI-T UT210E. I bought it because it I found some good reviews about its accuracy in DC Current measurements with the clamp. Cost was around £40, which is less than I would spend on a good night out when we can again.

 

3 hours ago, Marty... said:

Thanks Tom 👍

I  have removed two screws but it seems held together with hot moulded pins any thoughts on getting it apart?

 

All you can do is carefully lever all the way around the edge with a flat, thin tool.  It's not meant to come apart so there's no easy/failsafe way of doing it.

Hello,thanks Tom,I photographed the layout then removed the fuses and it came apart with a little leverage,no other fixings 👍

I cleaned up the board and socket as best as I could with iso and some electronic switch cleaner with cotton buds and a small plastic scraper,a split down incense stick stub for the socket flooding with cleaner then poking and wiping,the battery drain is still there and the central locking has now stopped working on the drivers side 🙄

One of the pins was really corroded and tomorrow I will have a go at making and fitting a new one

The meter I bought was an eb8y job £20

 

Hello,the big question...am I wasting my time? Has replacing the fuse/gem assy fixed this problem for anyone? anywhere? I can't seem to find much info regarding success and I don't have means to replace right now anyway but really do not want to spend a few weeks saving up for a new/used one only to be even more disappointed.

 

Thanks again

Marty

You're doing well👍 Can you check out the soldered side of those pins...maybe that heat has caused the electrical  joint to weaken.    Also, consider the plug and suspect that the heat will most likely have caused poor electrical integrity on the socket pins too. 

Thankyou 👍

I did check for dry joints and all looked good,I will take the module back out tomorrow and give it a good drying out as I believe moisture can sit in the board and blow it when trying to desolder.

I will research the socket 👍

Hello,a couple if photos of the board after initial clean up,I did clean up some more today and made a tool to scrub the sockets from a dental floss brush.

After installing in the car and connecting the battery the central locking is now working again,I ran out of time today so could not test for drain but my thoughts are the unit is not trustworthy as I believe moisture is trapped in the board scattering the current?? not sure of that though 🙃

There is continuity between all relevant pins so all still connected not rotted through.

The photo to me shows moisture in the board.

I have read that replacing with the same requires no coding so I will search for like for like first and if need be I can sort out an elm lead and recode.

Thanks