Car would not start so I check the battery compartment and there was water. Also some white powder on battery terminals, not much tho. Clean it with baking soda and water. Replaced battery with new one. But car won't start if it sits overnight. Alternator is works and charges. Did the water damage something or is there a draw some where? 04 mini cooper s jsw. Thanks for any help.

 

You can find out fast if you know how to use one of this.

 

Don't have one :( Only have one of those cheap computer reader with Bluetooth which I use to check voltage. Its was at 14.2 when car was running and 12 when car is off. But would drop after checking it a couple hours to 11.8.

 

Need to have something that can monitor the voltage and then start pulling fuses. I would start with those in the engine compartment first. Item 0023 in the below link will take to a thread with all the fuse/relay information. There are several fuses under those you see when you pull the cover off. Need to remove the air filter box and the ECU in order to access them.

https://www.northamericanmotoring.co...questions.html

 

Voltage will stay the same regardless, you have to monitor the amperage to find a current leak, as you pull fuses.

 

I agree with DneprDave on this one. Someone posted a link to an "Amp Clamp" similar to the one shown in post #2 earlier this week for an excellent price.

EDIT: Found it. It was posted by pnwR53S.

 

Just trying to teach some to fish, instead of serving up a fried fish ready to eat.

 

 

The old style amp probes will not work as they only read AC amperage. The battery voltage will drop if there is a draw. Anybody that has done a remote flash tune of the ECU is aware of voltage dropping during the tune.

If you have the proper tools for reading DC amperage fine, if not, watch the voltage with a digital read out, not analog.

 

That ain't the old style amp clamp. It read DC current, from 100A down to a few mA. 65mAdc read in the photo to be exact.

 

Just take the positive lead off the battery and put an ammeter between the battery cable and the battery. All the current being used will show on the ammeter. Then pull one fuse at a time and note the current draw on the ammeter, When you pull a fuse and the current loss drops off, you've found the circuit responsible for the current draw.

 

I know that as I have the old style because I am old. My comment was to another old geezer as myself that will read this thread and think an old black analog amp probe might work and to the thread starter that could only monitor the voltage.

 

Cool! I could never justify one of those inductive clamp meter. They used to cost $500 and up. It is amazing what you can get for so little money these days. A hall effect AC/DC current probe alone for a Tektronix scope used to cost $1050 a decade ago. Now you can buy this little meter for $35. This is the first clamp meter I bought. I gave up teaching people how to measure current with plane old DMM if they don't have the basic fundamentals of electricity.