So my 2000 Civic EX with a D17y7 engine is not charging the battery.

I went to check the alternator and found a rusty and almost broken connection (picture attached) , so I automatically thought that was the problem. I removed that plastic covered connector piece and hooked the wire lead strait to the alt. (the connection between the alt and the wire lead was fixed)

The voltage still read only 11.7 while the car was running, and the car died as soon as I disconnected the battery.

So I though the alt was bad and took it to O Riellys and it checked out fine.
Also took it to a Napa, and they said it was fine.

I checked all my fuses, nothing is blown. What else should I check to get this fixed?

 

Check that there is battery voltage on the big output terminal of the alternator, at all times. With the engine running, put one probe on the alternator and one on the battery + and confirm there is negligible voltage drop. This circuit passes through the underhood fuse box on the large white wires.

Check that the black and yellow wire to the alternator gets power with the key on.

 

with the engine running, I checked the voltage on the main output of the alternator and it only read 1.5v

is this because there is no load on it?

 

That means the circuit from the alternator to the battery (through the big white wires) is open. Are you sure the alternator fuse in the underhood fuse box is OK?

 

yes, the fuse is OK.

Where would I look to find where it's open.

 

when you say put the probe on the alternator, do you mean on the outside of the alternator (ground) or on the main output terminal on the alternator?


also there is no voltage in the black and yellow wire with the key in the ON position.


let me know, thanks!

 

Put the voltmeter - black probe on ground for both of those tests.

Red probe on the output terminal or on the black and yellow wire. If you don't have battery voltage on the output terminal at all times, probe in the fuse box, where the big white wires go in and out of the fuse box and on both ends of the fuse to see where voltage is being lost.

 

check for continuity on the alternator fuses....even if they look good

make sure there is no corrosion on any battery post/cable

check for continuity in all the wires leading from the alternator to the battery. It may look good, but just to be safe disconnect the wire from the alternator fuse and check continuity from + battery connector and end of wire where it mounts to fuse.

there's a break somewhere in that line whether it's a wire broken/cut/frayed or fuse blown, has to be.