Dear EM2 family,
My 2k3 2dr Ex is having a battery drain....started 4-5 months ago, swapped 3 batteries, 2 alternators(1 junkyard) (1 brandnew current), 1 starter new...when theres juice its a smooth start and a smooth ride...however...battery is still being drained...so i cant start car, slow turnover w/o a jump...any ideas??? plugs r new...battery, starter...alternator all new!!! fuses all good...master relay is good....HELPPPP...b4 suicide jk

 

do you have an amp ? could be staying on and draining your battery.

 

there would be if I didn't have this problem...but im all stock. all i know is that it was a show car b4 i bought it...but theres no extra wires that i have found

 

Hey there. i have a few things you might want to try.
first of all list ALL aftermarket electrical accessories....aka autostart, alarm, foglights, stereo etc. this will greatly help out ability to help you.

secondly, do a parasitic draw test (i would have done this after replacing battery #1 and before all else) to do that you simply:
-turn off all loads (everything that's on) (remove your key, close the door etc, only thing open is the hood and driver's window)
-disconnect the negative terminal of the battery
-grab your multimeter (go buy one they are expencive if you get a good one (recommended) but TOTALLY worth it...aka it would have been cheaper than the parts you're replaced....expect to pay 200$ or more for a good one...if you are not sure how to use one properly, maybe start with a 10$ one.
-put yourself to the milliamp setting and (i use crocodile clips, or clamps) put the red wire of the meter to the negative post of the battery, the black wire to the negative cable of the battery
-you will see a draw for sure at this point. you have to leave it like this for 5 mins or so so that the pcm can go to "sleep"

if your reading after 5 mins is something like 10mA to 20mA or so you don't have excessive draw meaning its probably a battery or something.
if after 5 mins you have more than that you have excessive draw...start unplugging your aftermarket accessories (easiest way is to pull the fuses) until it settles to 10-20mA...in my 4 years of doing these tests its usually an excessive draw in an alarm or auto-start

let me know how it worked out and i can help further

mind you, of you get 0mA or OL reading, you probably blew the fuse in the multimeter...replace it.

it's very important to not open the doors or anything when doing this test because the dome light and the other loads (dash lights and pcm waking up) can blow the fuse in the multimeter

 

clean your battery terminals.

take off the terminals then clean them w/ coarse sand paper. i've seen ones that looked fine perfectly fine but my multimeter showed a huge voltage drop across them. everything was fine after using sand paper to remove the corrosion.

 

my money is on a stuck relay seen soooooooo many about 1 a week anything under 30mA for that car is good anything over is not so good

 

thanx for the tips however I had honda do a diagnostic today...the summary was that the parasitic draw was normal 14ma no after market alarm or autostart is in my em2...as of now I have no starting problem the alternator tested good and my battery is full charged...but four days ago they did my oil change and they good barely pull the car in the bay as it was slow to crank. after the oil change they recommened I replace the battery which was at 230 cold cranking as oppesed to 435...today the same battery is fully charged!!! i am stumped- also the terminals make sense...but the battery is brand new! I'm gonna commit murder suicide....kill my car then myself! jk

 

If the terminal clamps are corroded and the mechanic is clamping the load tester onto the battery clamps to do the load test, that would cause the cranking amp number to be low.

 

i do have brass clamps to replace the stock ones but i have no idea as to how to replace them- but i will try doing so soon...thnx evryone! u guys are all smart as hell!

 

just take sand paper and clean the inside of the terminal clamps...scratch up the metal as best you can.

 

oddly enough both my electrical problem and my fluctuating idle are gone...I don't know how but they are and its running like brand new...for now Im gonna keep an eye on it...but move on to my brakes and body work before winter...slotted and drilled...keep ya posted and thanks to everyone for the tips! p.s. mayb honda tweaked it somehow and B.s'd me with the diagnostic results saying there was no problem?? cause they saw the clear problem and recommened i get it checked and now poof its gone??