94 Civic Si
JDM B16A OB0

Had this car for 17 months

Was driving on the highway for about 3 minutes at 3K RPM going 60mph. Then was slowing to a red light I put my transmission in neutral and I just saw my rpm hit 0 So I got her started with the help of a fellow driver via push start. The car tried to die a couple times whenever I put the car in neutral to slow down at a traffic light so I just held my RPM's near 2000RPM.

Battery light is NOT on
Voltage at idle (900 RPM)with no accesories on: 12.65
Voltage at 2000 RPPM with no accesories on: 12.81
Volatge at idle with headlights, defroster, radio, and domelight on: 11.68

Is my alternator bad?
Is there any other tests I can do?
if it is my alternator...I don't know which one to order since I have a JDM B16A and the alternator?

 

It could be your battery that's dead. If alternator is bad, car won't even start after a few cranks.

 

That's the thing...I bought a new battery and charged it.

 

12.8 with engine off is ok


12,8 with engine on is not ok


alternator should be putting 13.8/14.5 at the battery with the engine on

 

Alternator is on the way out.

Batteries and Alts generally **** up together

 

i thinks its dead lol.

just double check your alternator fuse.

 

time to replace the alt ... At idle voltz should be at 14.xx

 

i agree....its bad ... replace it

 

Thanks for all your input guys!

Now I don't know what kind of alternator to buy. What vehicle should I order it from since it came with the JDM B16A OB0 motor?

 

1990 1991 integra..

or you can use a sohc alternator from a ef just swap the belt...

 

Update: It's not my alternator...

I looked at some alternator threads and I found one where the guy was having the same problem as me. When he changed his alternator he was still getting the same amount of volts.

So I didn't buy an $100+ alternator. I did some more troubleshooting with the charging system. Alternator fuse is good...continuity from alternator connector to battery post shows good and only had .002 of ohms. Next was to look at my grounds. ALL OF THEM WERE CORRODED!

I cleaned the grounds up especially the G101 which is at the thermostat. Did a parastic draw test...results 3ma of draw compared to when I tested it like a week ago it had 7ma of draw.

Tested the battery volts and it was at 12.30 not really good in my book but the car started like it was healthier than before.

Idling with no accessories on: 14.28 volts
idling with headlights, defroster, ac, and radio on: 14.10 volts

Now time to go driving around and see how she does.

 

Why is 12.xx voltz not good in your book? Thats perfect voltage for a non running motor

 

Because it means its .1 volt away from not cranking my motor. when I tried cranking it at 12.20 volts it just makes a click