Okay something keeps draining my battery while the car is off.

I've changed batteries twice (both to new ones) and have had my alternator changed with a known working one.

My car reads ~ 13.4 w/car on and a new battery

After a while this goes down everytime I check after the car is off.

If I leave the car off for say 12 hours it goes down to 11.9 with the car off for a while. I can jump start it just fine.

I searched honda-tech and read on using a multimeter to see what is drawing power while the car is off. However the directions were not that clear.

Anyone want to give me clear directions on how to do this? Thank yoU.

 

anyone?

 

I would consider disconnecting things like the ECU, security system, radio and system if you have it to see if any of those are the culprit. Some other ideas off the top of my head include EVAP and fuel pump (main relay) staying on after the engine is turned off.

Adi

 

yes but how do you test that with the multimeter?

it has something to do with the ohm (resistance?)

 

You need an ammeter to measure for current going through whichever device you're testing. Or maybe connected in at the battery to comfirm first? You need to be careful when doing that though, you can do some real damage if you don't know the difference between measuring amperage and voltage.

Sorry I'm no help.

Adi

 

thanks.


anyone else?

 

bumpz

 

anyone else?

 

set MM to amp. disconnect one afust at a time, like radio/cig ligther, pull the fust out the fusebox connect the MM leads to each end of the where the fuse sits, read the current drawn thru the MM. replace fuse, move on to the next like horn or lights, or wipers, etc.
if you dont catch it by fuse. check for any leads directly to the battery, maybe previous owner installed an amp and went directly to battery with an inline fuse, etc.

Greg

 

Pull out every fuse one by one from the fuse box and look for the multimeters current to drop.

 

what do i set my multimeter too?



That is what mine looks like.

 

It could be your alternator not charging the battery, give it a shot...

 

You can get an iscope.. Check amperage on vehicle.. turn off all accessories leav scope on.. then one by one remove fuses, if you see a noticeable drop in amperage from the fuse.. then check what fuse it is and that will pin point where it will be coming from..

 

What is an iscope?

And my alternator is good, it's been tested and another has been swapped in

 

Easy way with your multimeter. Set it for Dc where it will measure the proper car voltage ( on the image you will turn it 1 click counter clock-wise on the 20). Disconnect your negative terminal and use the multimeter to bridge the gap. It should read something around 12v.

Disconnect fuses of devices that shouldn't be powered when the car is off. If the voltage drops alot, you've found your problem.

 

You see the A--... ? That's amps. Put it on the 10 (the largest number)
for 10 AMPs.

I would start at the engine bay fuse box and work your way into the
interior. My battery drain was on the alternator (had to replace it)
so you may not find it on a fuse. the alternator goes direct to battery.

you also have to move your red test lead to the upper lead port.