Headlights dim

[chuNknorris]

I noticed an odd thing last night. Ive never seen this before so I know its not a normal thing. Whenever I would turn my blinkers or break lights on my head lights would dim to the point of shutting half way off??? I know this is common with electric windows, but I wasnt using them and I was at relatively high RPMS for the headlights to randomly dim.

Is my alternator bad or battery you think? I dont have a volt meter so I cant go out and check the battery.

[chuNknorris]

Vortex is saying its a normal thing, but Ive never noticed it, and its by far not normal.

[DSV]

Could it have to do with the extra power going to your additional rear brake lights? IDK, just throwing that out there. You could have a worn out ground cable in the engine bay somewhere. I've heard lots of people say that upgrading your ground wires is a good idea. :tu:

[chuNknorris]

Soooooooooo they didnt do it last night????

[DSV]

Soooooooooo they didnt do it last night????

Weird. So it sounds like its not a constant problem, but obviously there IS something wrong. That almost leads me to believe that there is a loose connection somewhere or something that is just barely tight enough so that it could be jarred loose and cause your issue. IDK.

I'd still take it to O'Reillys and have them scan the batter and alternator.

[lenny]

Battery....Try cleaning your cables. Take it to an interstate battery or batteries plus. Their tests are far better than the standard "load" tests that Advanced, Autozone, etc does.
-Dan

[iadubber]

Yeah, get the battery tested first. Clean your terminals. Check your grounds in the engine bay. If none of that at least help it, then it may be the alt., but I doubt it.

[vrjetta98]

Yeah, i have had the same problem but it is when my subwoofers are turned up and i just left my driveway. i think it is just that i might need a bigger battery becuase my battery is brand new and cables are pretty new.

[iadubber]

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[OrangeDUB]

Battery....Try cleaning your cables. Take it to an interstate battery or batteries plus. Their tests are far better than the standard "load" tests that Advanced, Autozone, etc does.
-Dan


Yeah, get the battery tested first. Clean your terminals. Check your grounds in the engine bay. If none of that at least help it, then it may be the alt., but I doubt it.

Once the car is started, ALL power is supplied from the alternator. Have your alternator tested, not the battery....

If you have a good alternator, you should be able to run the car without the battery once the car is started, so I would start it, then disconnect the battery and see if it dies. The alternator may be only partially charging.

[vwmeister]

Once the car is started, ALL power is supplied from the alternator. Have your alternator tested, not the battery....

If you have a good alternator, you should be able to run the car without the battery once the car is started, so I would start it, then disconnect the battery and see if it dies. The alternator may be only partially charging.

With all due respect sir, disconnecting a battery on todays modern cars while it is running is not a good idea. WAY to many modules/ecu's that can get fried. Most places, including mine, can test the entire starting/charging/battery system in one procedure. Usually takes about 10 to 15 minutes.

[DSV]

Most places, including mine, can test the entire starting/charging/battery system in one procedure. Usually takes about 10 to 15 minutes.

Exactly. O'Reilly's also has a testing machine that hooks up to the battery and tests the starter, alternator and battery all with one connection. :tu: