charging issue with my drift car running 15.5volts

[slider4life]

Hi guys

ive got an ae86 drift car with an sr20det in it i noticed the other day that when the car is running it was producing 15.5volts so thought ok alternator was in need of replacing so i got a second hand one fitted it same deal. so i thought unlucky got a dud one. borrowed a mates one off his car that im 100% works fitted it up and still dose the same thing??????

now i was told that i need to have a battery light in there for it to work right??? is this correct and if so how do i hook it up and to which wire off the alternator dose it go to??? thanks for the help

[Matt]

Generally yes you need the charge light hooked up.

[the witzl]

Yep - hook up the charge light... otherwise the regulator isnt getting a voltage reference and will give full output.

[slider4life]

Yep - hook up the charge light... otherwise the regulator isnt getting a voltage reference and will give full output.

yeah i get i need it but how do i hook one up as i have a full alloy dash in the car do i just use a pilot light and put it in line with one of the alternator wires?????

sorry for the dumb arse question but only have a week to fix it before next round

[Matt]

Run a new light somewhere.... 12v ignition to one side and the alternator pin is effectively the earth.

[the witzl]

what Matt said.
Ign 12V+ to one side of the light, and the other side (earth) goes to the charge light pin on the alternator.
When the alternator isnt working, the charge light pin pulls to earth and the charge light illuminates on your dash.

[pt_y2k]

Nissan alts also have a "S" terminal,its a battery voltage sense wire,ya sure tis is connected? in the small 2pin plug on the alt the heavy wire(normally white) should have 12v at it when not connected to the alternator...

[the witzl]

Yep, if the nissan alternators have that "S" pin, it MUST be wired to battery positive terminal via a fuse. If not connected, this could also explain the high output voltage.

[slider4life]

Got it sorted guys thanks heaps turns out it was wired backwards from old owner. Now it charging at 14.3 volts. Only issue now battery light is always on???? Do I need a resistor or something in line??? Thanks again guys

[meadan]

Is it an LED or normal globe?

If LED you may need to run a resistor..

[slider4life]

It's just a pilot light from narva don't this it's led I'll change it to another light and see what happens.

CASE CLOSED THANKS GUYS