i have a power drain problem...ive been over the car and also had an auto electrician check it..cant find a prob my question is..if a relay was occasionaly sticking would that elec devise be on? i cant imagine it would..cus theyre all ign on thingys, but say if the hrw relay stuck..would the window be warm all night?? any other batt drain ideas Edited by: pigbladder
I've no previous experience with trying to track a battery drain problem on a car. But if I had to, I'd stick an ammeter in series with one of the battery connections and progressively remove various relays, fuses and so on, until I narrow down which particular circuit was causing the current drain.
thats what the elcetrician did.he said it was fine. then i tried again when i got home..im not totaly sure how much to expect i mean the alarm,clock, radio memeory use a little...what would be a reasonable amount?? and i cant test with the alarm hooked up cus the window closer cuts in and blows the 10 amp fuse in the multi meter
One thing I would also try right now is to go out and remove various relays, fuses etc and see if this has any effect in the morning. Just a thought. If an electrician was actually there having a go and still couldn't find the problem then I'm stumped. I guess you've eliminated the battery, right.
Hi pigbladder, There is another way to test current drain. If you get a really high power, low value resistor (like one off an old heater resistor) and put it in series with the battery, then you can measure the voltage drop across the resistor. The voltage drop is proportional to the current flowing through the resistor (good old Ohms law). You need a low value resistor (< 1 ohm) otherwise you'll rob too much voltage from the circuits you are trying to test. If you can't find a low value one, try several in parallel - watch out in case they get hot. As for the cause, sticky relays just don't sound likely. I would put my money on the alarm. As an aside, my central locking pump went strange a few weeks ago (loose wire) and didn't cut out after a few seconds. Hence it ran all day and completely flattened the battery. You could only hear it with your head in the boot - which is why it took me a few hours to track down. Simon.
trev..it wont do it overnight,it takes 5-10 days to go flat anyone know how much drop is acceptable on a good car..you know with the clock ,radio memeory ,etc? Edited by: pigbladder
5-10 days would suggest to me a dodgy cell in the battery, but Iassume that the 1st thing an auto electrician would check would be this?
sorry, 5-10 days are you running it inbetween or is it a fair weather car? If running inbetween it has to be a battery fault.
its happened with several new good quality batterys over the years...yeah i try to just use it in good weather and it can stand over a week with being touched
When my car is first connected, the radio pulls 200mA for a few seconds, then the car draws 30 mA. If it were a 1 ohm resistor, this would show up as 200 mV then 30mV. With a 0.5 ohm resistor, the voltages woudl be half that. Simon.
