Question-------------------------
Followup To
Question -
Dear Josh, I have BMW 320i 1981. Today after I turned the engine off and took the ignition key out, the battery charger/warning light came on. What is the possible cause of this? However, when I started the car again and turned off the engine and took the key out, it acted normal. i.e, the light did not come on. Any thoughts? Thank you in advance.
Answer -
Jfar,
Unfortunately I am not that familiar with the E21 BMW's, as I know mostly about the later E30's. Remember, the car is over 20 years old, so wiring connections as well as the rest of the car are getting old. It could be a loose connection on the starter or battery that triggered this light. usually this light will come on if the Alternator is failing, to let you know that you are about to run out of power. The other thing is, you might need a new battery if you start having problems.
It's nothing I would be too worried about, just take note of the battery voltage over the coarse of a couple days. Like take a multimeter and check the voltage in the morning, then after you drive the car, check it again. and compair the two. When you check the voltage in the morning, you should have at least 12volts. if it jumps to 12.8V or 13.0V after you drive it, you have something that is drawing current while the key is off.
Make sure the Alternator is working as well, you can test voltage, then start the car, and see how much, if any, the voltage increases by testing again. I think most cars should be close to 13volts with the engine running.
If you have less than 12volts, something is probably wrong and you have something draining the battery.
Hope this helps some,
Josh
Dear Josh, Thank you for your prompt response. I dont understand the electrical/mechanics of the car but I will have the charging system checked by someone. you said it could be a lose cionnection on the "starter". Is that also related to the battery charger light? I thought the battery light only related to alternator?
One more question. Could this light might be coming on because of a failed or bad relevant fuse? On BMW Board, I read this and I quote <Don't forget to check the fuse that controls the light circuit, too. This fuse could be labeled differently in various cars. It could be labeled "charging", "regulator", "meters", "gauges" or "engine". In some cars, if the fuse is out, the idiot light will come on but may not go off. In others (like GM), a burned out fuse may make the warning light work in reverse order; that is, when the key is on, the light is off but as soon as the engine starts and the alternator starts charging, the light will come on.> Is "idiot" light the same as Battery warning light?
I thought if the fuse goes bad, lights dont come on at all.
Any thoughts?
By the way, today it only happened once wheh I took the ignition key out and the other 3 times, the light didn't come on ( which is how it should be ). The first time I paused a little before taking the key out, if it means anything.
Regards.
AnswerJfar,
To be honest, it could be several things. Like I said before, I'm not as familiar with these older cars. This light usually means that something is not grounded correctly or the battery is weak or something like that.
The Starter came to mind, because it is a main circuit that comes from the battery, and if something happened to come loose (even this one time) then it "COULD" have caused this light to flicker or come on. It could be several things.
In my oppinion, I would not worry about it. It may have been a glitch in the system, or some random occurance that this light came on. I would keep driving it, and if it comes on again while driving, then I would take note of it. If this light is only coming on when the key is being turned off, it's probably some wiring issue. If you were driving and this light came on, then it could be the battery or the alternator.
Like I said, have the battery checked for anything draining the system. Be careful by taking this to a shop, as they are probably going to say "Uh.. it's your battery... you need a new one" with out even trying to find the real problem. So unless you are friends with your mechanic, they will rip you off.... all of them!
Good luck!
Josh
