battery light. new batt and alt !!

[sho4life]

will underdrive cause this?

 

[Phoenix]

will underdrive cause this?

No but a bad alt will , or messed up wires (corrosion-bad connection)

 

[sperold]

Hunt around and find a gauge that measures from 0 to 15 volts, or a bit higher. The less expensive multi-meters have the first range ending at 10 V and the next range ending at 250 V, so the band you are looking at is not well served.
I checked my alternator and it put out 14 V at an idle and did not put out any more at higher rpms, so look for something like that.

 

[sho4life]

the test at autozone was good. maybe that wire to the alternator is bad. i drove for hours at night at its fine. maybe ill just unplug the bulb and add a volt guage.

 

[Phoenix]

the test at autozone was good. maybe that wire to the alternator is bad. i drove for hours at night at its fine. maybe ill just unplug the bulb and add a volt guage.

Its been said and done numerous times. Those bench tests are not detecting what 'your dash' detects. Change the alt and live on. Theres most likely something wrong with it. In my opinion 95% of the times , when that light comes up , its the alt.

 

[sho4life]

great, i bought it from a guy on here and he said it was rebuilt. it looks nice and clean. how come it didnt **** the battery then?

 

[sho4life]

how bout a cracked case on it? would that detect something wrong?

 

[Phoenix]

great, i bought it from a guy on here and he said it was rebuilt. it looks nice and clean. how come it didnt **** the battery then?

Because its prolly charging at 50% , Its quite easy to check. Engine on , with a multimeter on Volts , check the batt voltage. It should be in the 14.4V range , - or + .5 , if its less or more , its doing it wrong. It will screw up your batt if you wait too long.

how bout a cracked case on it? would that detect something wrong?

I dont think so. You mean the alt case is cracked?

 

[sho4life]

yeah, it was at 14.6 and yes the alt case is cracked

 

[trainguy1989]

My battery is in the trunk and at the posts it reads 13.8 Volts. My Battery light has never come on in my dash. I know it works because it is lit in the RUN position. Are you saying my alternator is already wearing out because it was rebuilt 750 miles ago? Or is there a voltage drop because the battery is in the trunk?

 

[jmpSHO2nd]

My battery is in the trunk and at the posts it reads 13.8 Volts. My Battery light has never come on in my dash. I know it works because it is lit in the RUN position. Are you saying my alternator is already wearing out because it was rebuilt 750 miles ago? Or is there a voltage drop because the battery is in the trunk?

I believe the battery light will come on some where under 11 volts and to me 13.8 volts at idle is good.

 

[sho4life]

my light is possessed. i just installed a 1000 watt amp and additional 55 watt driving lights. still reads 14.6

 

[jmpSHO2nd]

my light is possessed. i just installed a 1000 watt amp and additional 55 watt driving lights. still reads 14.6

I wish I was that lucky.

 

[Cl-Slick]

I am having this same problem! I was driving to work today and the battery light would come on when the car ran over 1500rpms. On my way home from work, the light stayed on, and the A/C quit at one point. I just put a new battery in, but there is a frayed connection on the alternator. After the car cools down I'm going to fix the connection and see if that's the problem. If not, I'm replacing the alternator tomorrow. Any other ideas on my problem?

 

[Cl-Slick]

This thread is describing problems very similar to mine...http://www.shoforum.com/showthread.php?t=108658&highlight=battery+light

 

[Cl-Slick]

New alternator is in and the problem is solved. The removal/install is very easy and straight forward!

 

[sho4life]

well here is one for you guys to wonder about and put in the mystery hall of fame, i washed the engine bay and the light went out

 

[luigisho]

Power wash?

 

[sho4life]

yes, strange huh

 

[luigisho]

Maybe you gave it an aquatic wiggle test. Might be a loose connection somewhere.