SSSunny

Please help me figure out this problem.

So i thought my alternator died because my car stoped on the road and wouldn't start without a boost. Got a New/ rebuild alternator but i still couldn't get the car to stay started with out the jumper cable connected from another car. i even got a brand new battery and i thought that fixed the problem till the battery died on its own after an hr of running the car. this told me that the alternator isn't charging the battery or anything else in the car and that my old alternator might have been okay. now i even changed the alternator plug, properly soldering the wires for a good connection. AND STILL, the alternator isn't powering the car and it dies the second you take off the jumpers.

The car is a civic with a non v-tec B-series swap. could it be my wiring? ground issue? my chipped ECU?
Any suggestions ?

chris_v2

Why not start with the basics.

With the vehicle on, what voltage is the battery terminals at?
Now load the vehicle (blower on full, rear defogger, high beams, etc)
What is the voltage now?

SSSunny

ok, so i tested the battry and it was reading 10.5v DC and it dosnt start or anything without a boost so i can't measure the reading after i start it and check voltage with everything running ie blower, headlights.

rick10

maybe they sold you a dead alternator ...

You could check the alternator belt too, maybe it is loose...I read somewhere that a loose belt can cause the pulley not to be turned enough

good luck !

MPR

Bump-start it.

Check/clean the terminals on the battery and connections on the alternator.

Check the engine to chassis ground straps. Also check the cables from the battery to starter. At 10.5v the starter should do something. Sounds like a loose connection to me.

Do what Chris_V2 said and post up the readings.

JDMej1

maybe you have a draw, when you check what chris said, check for a draw. with everything off and all doors shut, lights off etc, key not in ignition, check if you have current flow (amps)

SSSunny

will do this weekend, thanks guys. car is parked at my rents place so i cant get to it till the weekend.
gona jack it up and confirm all grounds r good, belt is tight then check for draw.
And i changed 2 alternator because thats what i thought when i got the first one. but same issue.
i'll boost the car and let the battry charge for a bit, then take the boost cables off and see if i am reading more than 12v. that would tell me if my alternator is doing anything.

SSSunny

because as of right now, when u boost the car and take the jumper cables off it dies right away.... i still have warranty on my battry, maybe i should get a new one?

trunk_munkey

I think its the flux capacitor

MPR

Your engine should run without a battery, so what you just said tells me your alternator is not doing it's job.

SSSunny

yea, but the alternator is new so there is something else wrong like wiring or ground. when i replaced the alternator i checked the wiring harnest and it looked good and firm. can the ECU have anything to do with this ?

MPR

Ecu wouldn't cause this. It's probably the alternator or wiring related to it.

chris_v2

When an ohmmeter from the positive battery terminal to the positve terminal on the alternator.

You should have around .1-.3 ohms. Anything higher, you have an issue.

chris_v2

Run an ohmmeter** not when. lol

Big Ocker

Do you have a blown fuse and/or a code for the primary 02 sensor? Can't remember which one in the under dash panel; sometimes the code is stored even though the MIL doesn't light up. I've seen a lot of these cars have the wire harness under the intake wear on the manifold support bracket and damage the wire harness. Even if the plastic harness loom doesn't look bad the wires will chafe on each other inside the harness.

Neil.

danny1danny

with the car running, at battery, it should read close to 14v.
i would check this first.
did u fix the prob?.