My problem was that after running for a few min the voltage would drop at the battery and continue until engine died. put multimeter on altinator and saw less then 12v at idle. Put in new alternator but everything stayed the same. put in new battery and still no change. also when voltage gets low the rpms drop down next to nothing until it just cuts off. please help. 98 Accord f23

 

look for the big 80A or 90A or so Alt fuse in the engine fuse bay and see if it's blown

 

Hondas from the 90's-present, have a device called an electronic load detector. This device turns the alternator on and off during cruise. It frees up power/increases economy, until the battery needs charging or a high draw device(fans, headlights) are turned on. If you turn on your AC or headlights is there any increase in voltage?

Check your under dash and under hood fuses. There is a small ampacity fuse that controls the ELD, if this fuse is blown the alternator will not charge. Verify with a meter that the fuse is bad. If it is, there may be a short in your wiring harness. Check wiring harness, verify fuse does not blow(if it did) and the ELD should work.

 

both of those fuses are still good. When i turn anything on, the voltage starts dropping much faster. i could not locate any fuse for the ELD,would it be called something else? also i have noticed that the battery light never comes on in my dash.

 

Are you having any drivability issues? Are you checking voltage at the power B wire at the alternator ? What does the battery voltage look like ? Do tests with the car cold and warm . Like mike said, what does the voltage do when you turn on the headlights ?

 

thanks for the helps! I rechecked all the fuses and found that the "cruise/ecu" fuse was missing, guess one of my neighbors thought they could help themselves since the car sat for more then a month. running nice and smooth now with just around 14v at the battery.