2003 chevy silverado problems plz help....?
ok... yesterday i was picking up my fience from work and we stopped at dq on the way home.. when i look at the volt guage while i was idleing in parking waiting for my food, it was fluctuating... did get down to the 9 though... got the the bold white mark between 9 and 14... but when i am driving it stayin on 14 or a lil under or above... will i need a new alternator? o and when i turn the truck on to view the battery charge its on the bold white lin between 9 and 14... idk y my truck is doing this... o and the airbag light on the mirror is saying the passenger airbag is on... but off keeps flcikering... the truck is a 4.8l with the stock 105 amp alt. in it
Update:the airbag light is on the mirror... it for the passenger airbag... my truck has the option to turn it off and on... if no one is in the seat its is an auto off feature... if someone over 90 pounds wits in the seat it comes on..
Comments
Your alternator sounds fine, car batteries are 12 volt and the charge fluctuates with engine rpms's. Totally normal, nothing to worry about.
Although with your airbag warning your alternator may be failing, heres a simple test.
Start the car, make sure all the accessories are off and rev up the motor to a fast idle. Set the Voltmeter to the DC scale (not AC or Ohms). Measure the voltage across the battery terminals - red lead of the voltmeter on the positive terminal, black on the negative (ground in most cars). The voltage should, and probably will, read around 14 volts. If it reads less than 12 volts you may indeed have a failed alternator and you can skip the next step. Next, turn on the heater, the rear window de-fogger, the radio, the headlights and anything else that draws power. Now rev up the motor and watch the voltmeter. It should still be reading around 14 volts. If it reads lower than 13 volts the chances are that your alternator is not up to snuff.
You can go to Auto Zone and they will test the alternator for free. You don't have to remove it. You can also check the battery post and make sure they are clean and tight. My positive post was lose and my gauge was doing the same thing. This can cause serious problems. The volts drop but the amps increase because it's trying to pull more power thru the cable. It can get hot enough to damage components or even start a fire. Get it checked and fixed as soon as possible.
i would just take it up to auto zone they will hook up the computer to your truck and diagnose what is wrong with it. It's better to do it that way then to pay someone at a garage $50 just to hook up to your car. I found out the hard way.