I got a new battery installed and the voltage meter was still low. I showed my mechanic and he said let it run for a half hour or more, it shouldgo back up. I did what he told me and then I took it to school, and on my way back it started to get dark, so i turned on my headlights and thats when all the problems started. My instrument panel looked like a xmas tree and everything was going out of wack even my rpm meter was moving up and down like crazy. When I had to come to a stop because of traffic the car finally died and i had to get a jump. I made it home and it ended up dieing again in the driveway. Shole I find new mechanics or is this either an alternator, battery cables corroded, or a sensor problem? Please help me!!
A wise man onceshowed that when your regulator is faulty you'll often find your battery looks wet, from the acid boiling over, i was able to disconnect it and clean conecters to prolong it use for a tempory fix, its a whole cheaper to replace then your alternator if your unsure
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Re: Bad alternator? Or Bad Mechanics?
Hi if the battery is showing no charge on a voltage metre (usually around 13.5) and putting the lights on drains it than i would go for the alternator but first check the belt is not too loose, A little tip>>>> let the car idle and turn the lights on, then rev the car and if the lights dont brighten up then the alternator is not throwing out a charge, Hope this helps
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Need to have a meter to check continuity between new alternator and the new battery. Make sure all connections are tight. May have open fusible link which a meter will reveal. May have bad voltage regulator in the ECM which should show a code. I do not like relying on dash gauge, they can be inaccuate. Time to have a mechanic check for codes and continuity.
If you are using a voltage meter when the car is running check the volts coming off of the alternator they should be reading between 13.5 and 14.5. This will tell you if the alternator is doing its job. If not check the belt tension on the alternator
Connect a multimeter or voltage meter to test the alternator. Idle the engine. Check to see how many volts are showing on the meter. There should be 13.6 to 14.3 volts showing. Talk to your mechanic if your
alternator is not charging your battery. You can trade in your
alternator and your mechanic can give you a new or rebuilt alternator. Get A New Battery or Recharge The One In your Car. Hope This Helps. Alex :o)
Hello. Install amp meter on the battery main feed. One the amp meter is coupled
by direct or induced coupling. Start remove the fuses and watch the amp meter
and when the amp meter indicator drops that one of the circuit that have some
shorted or running. Now they can be more than one circuit that is operating when
First thing with the amp meter connect disconnect the alternator. Do get
wrong here. It a percaution if
you happen to concur a large short. Also, when disconnecting the alternator look
at the amp meter to see if there is a drop in current being used.
An alternator is a three phase AC generator. There are 6 to 8 high current
diodes hook up where it turn the three phase AC voltage to DC voltage half wave
+ side of the AC. Then this DC voltage being combined voltages goes to a
regulator which smooth out the voltage to 13.8 volts approx. The 13.8 DC voltage
is need to recharge the battery. Because the vehicle operates on 12 voltage
system it uses the battery for the constant voltages of 12 volts and a story
house of current. stewbison
have the alternator bench tested for faulty rectifier diode pack
it may be charging the correct voltage but it is AC voltage and not DC voltage
in which case the battery will die quickly
next to check is the voltage regulator
it has to be 4.5-14.8 volts DC and if it in the ECM unit , will require a new ECM to fix
You can isolate the new alternator by starting the car and disconnecting the negative battery cable with engine running. Now measure the voltage at the positive terminal to a ground. This will be your alternator voltage under normal load (w/o battery). It should be 14-15 VDC and closer to 15 if it's new. If not, return the new alternator and try again. If the voltage is normal, try touching the negative cable back to the battery terminal and see if it takes it back to 13. If yes, maybe your battery has an internal short.