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Weird car electrical problems
Typhoid Manny
Registered User regular
Registered User regular
I'm trying to help my old man work out some electrical problems with his car, an '02 BMW 325i. It goes like this: For maybe five miles after starting the car up, the blinker signals only work intermittently. The turn signals themselves work everytime, but the indicators on the instrument panel won't always light up, or they'll be up to like thirty seconds delayed turning on and off. The beep you get when you leave the key in the ignition and open the driver side door also stays on for a couple minutes after you take the key out and close the door. He took the car out today and said that the lights on the instruments and stereo both got very dim, and when he tried to open the sunroof it wouldn't open. Usually after driving for awhile, things start working normally again
I know a bit about electronics, but very little specific to car electronics. This sounds to me like there isn't enough power to feed all the components asking for it. It doesn't act like a loose connection somewhere and the battery is only about two years old, so process of elimination suggests to my uneducated self that probably the alternator isn't working as hard as it should.
Am I way off base here? Like I said, cars aren't my thing, so it's probably pretty likely that there's something here I'm not considering
I know a bit about electronics, but very little specific to car electronics. This sounds to me like there isn't enough power to feed all the components asking for it. It doesn't act like a loose connection somewhere and the battery is only about two years old, so process of elimination suggests to my uneducated self that probably the alternator isn't working as hard as it should.
Am I way off base here? Like I said, cars aren't my thing, so it's probably pretty likely that there's something here I'm not considering
from each according to his ability, to each according to his need
hitting hot metal with hammers
hitting hot metal with hammers
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A lot of car repair places will run a computer diagnostic for a reasonable fee. Sometimes they don't even charge one, in hopes that you'll repair the problem there.
-Indiana Solo, runner of blades
If that isn't the issue I would call around to some local shops and see if anyone does free diagnostics, or some might waive the diagnostic fee if you fix the issue through them.
A ground cable CAN have a loose connection though and that is a great thing to check first.
Do you own a multimeter/voltmeter? Connect it to the battery and start the car. The voltage should be ~14 to 14.5 V. If lower, the alternator is where you want to start investigating.
If the voltage is okay, start pulling fuses for non-critical things like lights and see what happens.
Taking the key out and stuff still drawing power also sounds like a capacitor not draining properly, or as others have mentioned a bad connection to ground from the battery (though Blaze's terminology correction is correct).