1996 Honda Civic ALTERNATOR

NEEDS2SPEED

MEMBER
1996 HONDA CIVIC
4 CYL
2WD
MANUAL
130,000 MILES

Hello, I really appreciate the help and advice you give on your site. My 96 civic runs all day without problems, but when I shut off the car and park it for more than an hour the battery dies. If I shut off the engine and disconnect the battery cables the battery stays ok. So for the past week I disconnect the cables everytime I park my car.
I checked the alternator in a garage and they told me its ok, the voltage was 14 and didnt decrease when the motor is kept running. But then the mechanic did something strange. He disconnected the battery cables while the car is running and it didnt shut off. It kept running.
please can you give me advice on this. Is it my alternator?

1 Reply

KHLOW2008

MECHANIC
41,815 POSTS

Hi needs2speed,

It is not the alternator that is faulty. What the mechanic did by removing the battery terminals is to confirm if the altternator is charging and the engine continuing to run indicates the al;ternator is indeed charging.

That is a stupid way of testing the alternator. For older vehicles without any electronic components, such test are acceptable. Newer generation vehicles have many electronic components that requires minimal current.

If the alternator is bad and overcharging, removing the battery terminals and reconnecting it can cause current spikes which could fry the engine computer or other components.

A voltmeter is the easiest way to test the charging and since the voltage was at 14. Why did they perform the stupid act?

You have a parasitic drain somewhere and when the engine is turned off, some component is remaining on. I would suggest checking if the cooling fans are staying on when the ignition is turned off.

Quite often when relays goes bad, the relay would stick and does not turn off when the activaating power is cut off.