I noticed my headlights along with all of the interior are flickering when the car is running. I don't notice it all of time, but I will pay more attention to it. The battery and alternator were tested at O'Reillys and the battery was bad. I replaced it and still have the same problem. The charging light doesn't turn on while driving either.

I pulled out the alternator and had it bench tested at O'Reillys where it tested good according to all three of their criteria.

I also noticed that the metal bracket that holds the battery down to the tray is starting to corrode. The metal is turning into a white powder much like you would see on a lead battery terminal. It is strange.

I ordered new battery cables and will see if that will fix the problem, because its hard to determine how much corrosion is on the covered copper cable. This seems like a possible ground problem, so I will go through and clean up all of the grounds in the engine bay too.

The lights stop flickering as soon as I turn off the engine, so my question is, can the alternator test good and still be bad?

I can go through the tests in the shop manual, but is there anything else I should be considering?

 

Resistor plugs? That's for radio interference though right? Leaky spark plug wire? Just guessing here.

 

Does it do this repeatably? Watch your voltage as this is happening. What if your voltage regulator is getting flaky?

Also...
Honda has a control scheme for the alternator, where the ECU can turn OFF the alternator completely for fuel economy. That's done when the system voltage is good, the battery's charged up, & there's no electrical loads (according to the ELD measurement).

Watching carefully, I've noticed the lights get dimmer & brighter on my former 95 Integra & 98 Accord. This didn't seem like a really fast rate, like a "flicker". More like switching every few seconds. Harder to notice on the 03 Accord, but maybe the system has become more sophisticated by that time.

There's a terminal on the alternator, I think it's labeled "C". The ECU will short that terminal to ground when it wants to shut off the alternator. If that wire is rubbing bare, it might short to ground inadvertentaly.

 

I had an alternator that "passed" the tests at the ALT. repair shop on the bench..I watched them do it a few times,but I insisted something was still wrong with it.The Tech then took it apart and DID find the voltage regulator was going bad.He replaced it and it fixed the problem.

Just make sure they look it all over...the bench test cannot simulate heat from the engine bay either.They do get it hot on the bench but it is not the same when it is bolted to the engine.If you have a bad regulator,it may not show up as a problem off the car.