Corksil

my battery is not charging. the voltimeter reads my battery at 12.5v and steadily getting lower the longer i drive.

my fuse 15 under dash is not blown.

my valve cover/chassis ground is solid, i just replaced it
my transmission/chassis ground is solid, i just replaced it
my alternator wire is clean and solid, my (circular) alternator plug is plugged in tight.

had my alternator tested today, it's perfect condition

brand new battery also.

what else can i check? give me something to diagnose......

b20vtec (b20z2 block/b16a3 everything else)

thanks

HondaPartsHero

I'll be honest I've had two alternators tested recently, one at Autozone and one at Advance Auto Parts and they both tested fine, but were showing the same issue as your car. One alternator was brand new that I bought from them and tested good. The other was my brothers 1990 Integra. So with both alternators I still went ahead and replaced them, and it was indeed the problem. I don't trust those machines anymore.

Corksil

okay, well my buddy is the one who rebuilt my alternator a few months ago, and tested it again yesterday. i trust that he knows far more than the 'autozone' 9-5 parts collectors.

Assuming my alternator is fine and my battery is brand new, what else can i test?

thanks HT

Corksil

teggi

if you have a multimeter, i say test for AC ripple, make sure the battery is charged. that is the only way you will know if the alt is good or not.

to your question: test the wiring to the ecu and to the fuse box. but if the alt tests good i would look further on the wiring.

Corksil

Thanks guys it turned of that my second alt wire was not connected. I had the alt charging wire grounded instead of to the fuse box. N00b..

I figures it out cuz there were two spots for wires in the fuse box but I had only one connected. I pulled the other wire off the nearby and and noticed the second screw in the fuse box was loose and the wire naturally relaxed right onto the screw. Thanks ht!

grumblemarc

iTrader: (4)

Corksil

Live and learn hope I didn't mess my alt up :@

95EG2

if ur volt meter shows 12.5v when the car is running that means ur alternator is bad... u should get a reading around 14.0 volts

grumblemarc

iTrader: (4)

You didn't read. He figured out what the problem was.

Corksil

yes i have a battery terminal with a built in voltimeter, very easy to know when you don't hook things up right.

and for monitoring voltage drop w/car audio gear.

thanks again HT

Debroy Smith

change the engine harness auto or manual don't matter I did that on my 2002 em2 civic and it solve my problem hit me up for more info

tony_2018

Good for you