Contour Enthusiasts Group Archives Forums General Troubleshooting Alternator/Battery issue

Battery light has been coming on at high rpms, then came on sooner at lower rpms, knew the alternator was on its was, finally it stayed on, then lost all power etc etc (this was over 3-4 weeks)

replaced the alternator, runs much better now, how ever at low idle in gear rpms (650 or so) the battery light comes on, soon as its in neutral or driving it goes away... im assuming the Battery is messed from the alternator going and at low RPM the alternator isnt putting out as much juice as the car wants?

(this is a 98 duratec, auto)

ideas?

Battery is only 6 months old and under warrenty regardless

Many people get the coolant light mistaken for the battery light...

Charge the battery well and test the battery and alternator.

Battery test. Engine off, headlights on for one minute. Voltage across battery terminals should be 12 to 12.5.

Alternator test. Engine running, voltage across battery terminals shold be 14 to 14.5.

When the old alt. seized up? If it was you could have worn the belt enough to cause this problem. Or if the belt has stretched to much this will also cause this to happen. I had that happen on my old car. Another thing to check is the belt tensioner. It should be really hard to push down. Also check the rest of the pullys to make sure they all move freelly (exept for the one on the crankshaft of course ) And of course last but not least, check ALL connections.

for more definitive reference, the serpantine belt tension should not allow you to flex the serpentine belt more than 1/4" up/down.