well when its morning the car is charging at around 14.6 volts, as she warms up the alternator drops to about 13.6 volts, which isn't enough because if I scan the car it shows 12.8-13.1 volts while alternator is putting out 13.6 or so at idle, now I mean I think that charging voltage is a bit too low, & because of voltage drop the pcm only sees around 12.8-13.1 depending. Now I'm wondering if this is purely temperature related as in when the car is cold its doing 14.6 range & when she warms up the voltage drops to 13.6 at the alternator, & in the morning the scan tool shows 13.7 or so which is great, I'm wondering why that is, is the voltage regulator inside the alternator going or is it the brushes if temperature has an effect.

Thanx guys, cuz I can pick up a voltage regulator & change it but preffer not to if thats not the problem.

Thanx again.

 

It is going to charge more after you start the car, because you just used a bunch of power from the battery. As the battery is replenished, the voltage will go down. That is what it is supposed to do. Mine sometimes charges less than that when hot and I never have a problem.

 

I know on chryslers/jeeps that battery charge voltage is dependant on batt./ambient temperature. The lower the battery temp the higher the voltage (14.7) The higher the temp the lower the voltage(13.1) The PCM sets these ranges with no load on the battery. Current demand is then determined by the regulator. When cold, 32deg or less with a high current demand the alt. can supply up to 15.3v.

On Lt1's its not as high tech. The regulator is solely responseable and makes adjustments based on the batterys state. A cold lightly discharged battery takes more voltage to charge. Because the current rate is slower through the battery when cold the regulator hikes up the voltage. When the battery warms current flow increases and the regulator drops the voltage down. With a warm fully charged battery and no load the voltage will be upper 12's to lower 13's because very little current is needed.


Kevin

 

Sounds absolutely fine to me. Mine does the exact same thing. 13.1 is exactly to spec I believe.