Hello, I have a 99 Honda civic, recently my wife was driving it. She said she bumped the exhaust going over a speed bump. After that the car's battery would not hold a charge and would be completely dead in the morning. Assuming it was a bad battery I replaced it. That did not fix the issue. After some diagnosing with a voltage meter it turned out the Alternator was pulling 2 amps. I replaced the alternator, that seemed to fix my issue but the battery light was on. I had the alternator and battery both checked. Both passed. I figured it was just a bad alternator from auto zone so I replaced the alternator again, this time around the battery light is fully on. I made sure to get the correct alternator as well, not the Canadian version. On a side note after replacing the alternator the second time my check engine light was on for about 2 days, (02 sensor) it has now turned off. Other forums say a bad fan motor. My fans in the engine bay work currently.

The car drives great now, holds a charge and has not died. I have checked to make sure the alternator is putting out good power and it is. I am going to pull the intake manifold and check for a short in the wiring from the alternator. Any other suggestions?


(What I have done again)
Replaced battery
Replaced Alternator x2
Cleaned all grounds
Checked all fuses under the hood and in the fuse box inside car (no blown fuses)
Verified that battery is holding a charge now.
Verified that Alternator is putting out power.

(What I am going to do next)
Inspect wiring from alternator in wiring harness

 

Bump

 

Unplug the 4 wire plug from the alternator. Turn the key on. The battery light should not come on. If it does, the wire for the light is shorted to ground. 1996 to 2000 models are prone to the "fuse 15 problem" where the wires that run across the back of the engine short out.

 

I have tried that, the battery light is off. I have replaced the Alt twice now, I am not sure what is going on. I am going to rip apart the intake manifold on Friday and check for any exposed wires. I am not sure where else to go from there...