Battery Indicator comes on when passing
#1
#2
If youve replaced the belt,and the problem persists,I suspect a defective alternator rectifier diode.Take it off,and have an auto parts store check it.
Keep in mind however that alot of auto parts stores (especially Autozone) will give you "bad news" just so they can sell you one. My personal opinion is if you have it checked,take it to two different places,and see if both agree.Of course if you take it to a reputable place like NAPA,you can pretty much rely that theyre giving you the "straight scoop".
lastly,if you do find its bad,do NOT get a reman from Autozone
BTW...Welcome to the forum!
Keep in mind however that alot of auto parts stores (especially Autozone) will give you "bad news" just so they can sell you one. My personal opinion is if you have it checked,take it to two different places,and see if both agree.Of course if you take it to a reputable place like NAPA,you can pretty much rely that theyre giving you the "straight scoop".
lastly,if you do find its bad,do NOT get a reman from Autozone
BTW...Welcome to the forum!
#3
Mine was doing that for a couple of years. I was just waiting for the rpms to come down when the light came on before I did anything.
Well, one morning went to start the truck and the guages all swept to the right, then back. Started fine.
Checked the battery that night and found it was going. It was origianal to the truck, 2001 and this was Dec 08. Put a new battery in, and the light no longer comes on.
Well, one morning went to start the truck and the guages all swept to the right, then back. Started fine.
Checked the battery that night and found it was going. It was origianal to the truck, 2001 and this was Dec 08. Put a new battery in, and the light no longer comes on.
#4
#6
Mine was doing that for a couple of years. I was just waiting for the rpms to come down when the light came on before I did anything.
Well, one morning went to start the truck and the guages all swept to the right, then back. Started fine.
Checked the battery that night and found it was going. It was origianal to the truck, 2001 and this was Dec 08. Put a new battery in, and the light no longer comes on.
Well, one morning went to start the truck and the guages all swept to the right, then back. Started fine.
Checked the battery that night and found it was going. It was origianal to the truck, 2001 and this was Dec 08. Put a new battery in, and the light no longer comes on.
Alternators generate AC voltage.There is an internal rectifier "bridge" that converts this(otherwise non useable) AC voltage to DC.It is then fed through the regulator,and to the electrical system. If there is a shorted,or open diode in this internal bridge,it will allow a certain amount of AC to be "inserted" into the electrical system of the vehicle along with the remaining good DC voltage.The load test however will recognize only the TOTAL amount of Voltage being output.Which in alot of cases will indeed be around 13.4-14.4 volts.The only way to properly diagnose a suspected defective alternator is a bench check,and proper equipment designed to measure AC and DC.The battery light is bascially a "clamped" circuit with a zener diode.This circuit is designed to illuminate the lamp in conditions of under/over voltage as well as sensing that more than a certain amount of AC is being generated by the system.
#7
My opinion is you need an alternator.
Reason is the brushes are not following the comutator at higher RPM due to wear and age.
The internal regulator detects this and lights the lamp as it is supposed to do.
Some store testing may not pick this up unless they spin it fast enough to see the problem.
4000 engine rpm is not the same rpm the alternator spins due to the difference in pulley sizes between the crank pulley and the alternator pully.
Reason is the brushes are not following the comutator at higher RPM due to wear and age.
The internal regulator detects this and lights the lamp as it is supposed to do.
Some store testing may not pick this up unless they spin it fast enough to see the problem.
4000 engine rpm is not the same rpm the alternator spins due to the difference in pulley sizes between the crank pulley and the alternator pully.
Trending Topics
#8
#9
BG-7 hit it right on the head. It used to be a problem with the old Generators and regulators of older engines.
Alternators are much better but it still happens. Very likely the brushes cant follow well because they are worn, or the rear bushing is loose.
Either way, you should swap it out before one of the brushes come loose and ruin the shaft.
Alternators are much better but it still happens. Very likely the brushes cant follow well because they are worn, or the rear bushing is loose.
Either way, you should swap it out before one of the brushes come loose and ruin the shaft.
#10
Thread
Thread Starter
Forum
Replies
Last Post