Nissan 180sx battery light staying on when started help

[gerryl87]

Hey guys, when I start the 180 the battery light is staying on the hole time, checked the alternator, it's putting out over 14 volts when running, put a new battery in an it went flat, I've checked the fuses beside the battery, any ideas on what it could be?

[alan opel]

What is the battery reading when running ?

[gerryl87]

It's reading 14.4 volts

[twincam 20]

Check the connection on the two pin plug on the back of the alternator, that sends signal to the clocks

[alan opel]

Check the connection on the two pin plug on the back of the alternator, that sends signal to the clocks

An is the battery draining when left sitting then? Sounds like the curcuit is broke on charging light circuit which is strange as usually won't charge with the light on

[gary g]

Disconnect the battery cables while car is runnin, turn of ligts radio etc first, if the car dies then its more likely the alternator.

[dude]

sounds like the regulator on the alternator idealy the alternator should be putting out 13.4/13.5 volts maximum at about half trottle and should not drop below 12 volts at idle under load lights and heater on ect thats the ideal situation but most alternators will go up as far as 13.8/9 14 volts but anything above is considered over charging and when the alternator is over charging it can also discarge your battery as the same components that regulate the voltage during operation can discarge the battery when not in use it when the alternator is over charging it can put the battery light on the same as if the alternator was not charging at all best take out the alternator and get it reconditioned

[gerryl87]

Cheers for that lads, might just try a new alternator when I get back to the car again