akllls

I have an eg hatch with a b20b and my altenator is not charging my battery I have taken both out of the car and tested them and they both are good before my battery during idle use to be at 13.4 and it steadily kept going Down until the car wouldn't start charged the battery at my job and now it idles at 12.8 when I charge it I noticed the cca were low so any ideas what would cause a good alternator to not charge?

Former User

Who tested the alternator? Why do you tryst the answer? Did they do the test correctly?

akllls

Well I work at a shop and I did the test myself before and after the battery died I just did it today and it passed 3 times with it putting out as much as 15 volts I also tried in autozone and it also passed there I searched the forum and a lot of charging proems are due to fuse 15 and an eld my car Canadian and it doesn't have an eld and my fuses are good so I'm stuck

Former User

The fuse 15 problem only applies to 96-00 Civics.

I recommend that you now test all of the alternator wires (the ones in the plug and the large wire). Does the charge light turn on when you turn the key from off to ON(II) (engine off)? Does the light remain on while the engine is running?

akllls

I tested the altnertor plug and two terminals were grtting battery voltage one was getting about 5 Volts and other was grtting around 2 volts I know the charge light doesn't come on when running I'll check later if it does when the key is on and the big alternator cable to fuse block has no resistance it also is receiving battery voltage off and on is there anything that controls the alternator output in egs?

Former User

It's important to know the details of how these tests were done and what specific wires were tested.

Former User

Please also give more details about this test. It sounds important.

akllls

Sorry What I mean is that I put my leads across the battery terminals to measure voltage and then took the lead out of the positive terminal and put it on the big white wire that connects to the alternator while the other is on the negative terminal I did this on and off and both voltage at battery terminal and at the alternator are the same
As for resistance I did a Voltage drop on the alternator wire from where it connects to the fuse block back to the actual alternator no voltage was being lost I took a step further and took an ohm reading and I got .01 ohms
And as far as the plug I gotta re do it only wire I remember was a black and yellow one that was getting battery voltage with key on

akllls

Okay I got the readings at the 4 pin alternator connector this was done with key on engine off and one lead on battery negative terminal and the other on the pin
Black and yellow wire 12.07
Yellow and green wire 2.47
Yellow and blue 12.07
Yellow and red 5.12

akllls

Bump for helP

Former User

I'm unfamiliar with these alternator wire colors. What engine wire harness are you using?

Was the alternator connector unplugged for your tests?

akllls

Yeah it was unplugged and i don't know what engine harness I got I do know it's obd1 if that helps

Former User

I think these^ are CRV wire harness colors and what you call yellow (bolded) is actually white (yellowing over time).

What ECU are you using?

Is an ELD CEL code thrown? Does the CEL work?

akllls

Yes the cel works I see it light up and turn off with key on and no cel on I'm running a p75 ecu

exb18c1

Do the maximum output test on the alternator and check the voltage drops on battery cables(pos. and neg.) to battery posts.Also did you check diodes (ripple)?Also check voltage drop in the wire between alternator and battery.Does all the cells in the battery are good?

akllls

The max voltage output is 15.4 volts I even put it on my friends car and it was putting out 14.5 volts at idle The diode was tested it's good There's no direct wire from alternator to battery it goes from alternator to fuse block then another wire out to the battery there both good and the battery passed a midtronics tester I'm not sure if that means all the cells are good though?

Former User

1) Your alternator has a 4P connector, which is designed for a car with an ELD in the hood fuse box. The Canada model has a 3P connector. In addition, your detection of voltage at the Wht/Grn wire in the 4P connector suggests that you have an ELD.

2) With the engine idling, you measure 12.8V across the battery posts, right? Do you read the same voltage across the two battery connectors?

3) Using the negative battery post as ground, what voltage do you measure at the large white alternator wire where it connects to the hood fuse box?

4) 3) Using the negative battery post as ground, what voltage do you measure at the large white alternator wire where it connects to the alternator?

akllls

1- if I do have an eld is it going to be noticeable because all I see in my fuse box is fuses and relays

2- terminals - 13.2 connectors - 13.2

3- 13.3volts

4 - fluctuates between 13.1 and 13.3

Keep in mind that this after the battery was charged on a vat so numbers aren't as low as before And another thing if it idles long enough all these voltage fluctuate between 13 volts to 13.3

akllls

Any ideas ?

akllls

Bump

Brettw0108

So I have a 2000 civic ex with a H2B swap and I’m having the same issue alternator isn’t charging my battery. Im on my 4th new alternator and have a new battery as well. At first it was cause I didn’t solder my alternator plug wires when I did the re wiring so had them solder started charging fine. Recently it stopped charging again I noticed my alternator ground wire broke again so I fixed it and still doesn’t charge. Also when i turn my key to one position before starting it my battery light isn’t showing but once I turn the car off it shows. All grounds and fuses seem to be good

Honda_lover136

2002 Civic.
When car is running, connected to battery, car will only draw from battery. 12v and dropping.
When car is running and I disconnect battery, car draws from alternator and battery cables show 14v.

New alternator, new battery, new ELD.

Challenge persists..

any suggestions?