Very dim battery light came on.
09-15-2007, 10:15 PM
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Very dim battery light came on.
I was trying to head out to a party tonight and I got half way there and my battery light came on but only very dim, not lite right up, I also noticed the sterio couldn't stay on with high volume (lack of power) So I turned around because I didn't want to get stuck somewhere. Then the light went out when I got back? Is this a sign my alternator is about to go out?
09-15-2007, 11:02 PM
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Sounds like the voltage regulator is going out or there may be a loose or corroded connection at the battery or alternator. Also check ground straps from the body to the engine.
09-16-2007, 12:47 AM
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I've had this problem with my 944s before. It can be tricky finding your solution, start with easy things like cleaning some grounds and checking the belt. You can roll with this problem if you keep your electronics use to a minimum (like don't use the AC, headlights and radio all at once).
09-16-2007, 04:20 AM
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Sounds like a loose accessory belt, to me. The alternator makes a grinding noise when it starts to fail.
Try tightening the accessory (alternator) belt a bit, with two 17mm wrenches.
There's a turnbuckle under the A/C compressor that tightens the belt. Don't overdo it, or you'll definitely wear the alternator out prematurely.
Try tightening the accessory (alternator) belt a bit, with two 17mm wrenches.
There's a turnbuckle under the A/C compressor that tightens the belt. Don't overdo it, or you'll definitely wear the alternator out prematurely.
09-16-2007, 10:37 AM
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yea I could try tightening it, I have the Delete Bracket so the belt is only running the alternator. And where is the voltage regulator? and how do i check it? also where are the grounds that might cause this problem? Also i was thinking that it could be my battery, the last few mornings it has cranked over slower than usual, plus that battery is who knows how old, so if it's not accepting a charge could it make that light come on?
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09-16-2007, 02:44 PM
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09-16-2007, 06:06 PM
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well what i was thinking is that the Battery light on the dash probably takes the voltage reading off the battery, so if the charge can't get through the battery completly then it would illuminate the light right?
09-16-2007, 08:12 PM
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it illuminates the light dimly because the batt is barely charging/12.6-.8v or less on dvm, when it stops charging the light is bright red.
that's why the light is on when the key is on and goes out as rpm's come up and the alt is charging the batt.
jump staring a vehicle has a lot of risks for the vehicle that's running and can kill that alternator if the cables aren't connected properly.
87951
that's why the light is on when the key is on and goes out as rpm's come up and the alt is charging the batt.
jump staring a vehicle has a lot of risks for the vehicle that's running and can kill that alternator if the cables aren't connected properly.
87951
09-17-2007, 09:12 AM
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Even if the cables are hooked up properly, starting the dead car while yours is still running is a good way to drag more amperage out of the regulator that it was designed to handle. Can you get away with it a few times? Probably. I do it on my truck pretty regularly. But its still not a good idea. When you start your own car (normally) your alternator isn't working yet, so it's never subjected to your starter under normal conditions.
Now - about that light on the dash - it's an integral part of your charging system. If the bulb is blown, your alternator will never get the initial field voltage it needs to start working - all of you who have to rev your cars up to 3k RPM before your voltage needle jumps above 12 know who you are, and yes, I'm talking about you. (If the alternator spins fast enough without a field voltage, it can "auto-excite" and start working by itself - kinda kinky sounding).
When the light is on dimly, it means you have field voltage, but the voltage regulator isn't putting out completely up to spec. This can be because of a bad voltage regulator, or a weak/failing alternator (or slipping belts). As alternators wear (the brushes, mostly) they produce less and less current at lower RPMs.
Now - about that light on the dash - it's an integral part of your charging system. If the bulb is blown, your alternator will never get the initial field voltage it needs to start working - all of you who have to rev your cars up to 3k RPM before your voltage needle jumps above 12 know who you are, and yes, I'm talking about you. (If the alternator spins fast enough without a field voltage, it can "auto-excite" and start working by itself - kinda kinky sounding).
When the light is on dimly, it means you have field voltage, but the voltage regulator isn't putting out completely up to spec. This can be because of a bad voltage regulator, or a weak/failing alternator (or slipping belts). As alternators wear (the brushes, mostly) they produce less and less current at lower RPMs.