Silvia Club of NSW

my car runs at around 13.6ish volts .. but at slow speed when i press the brakes harder to stop .. its drops down to about 12.8 volts .. Is this normal ?? or should it stay around 14 fairly constant .. maybe my battery is karking it .. thanx !

The car should from what i was told by NRMA dudes, run a consistent ~14 volts when the engine is running. If it doesn't this means the alternator is the problem.

If the voltage is draining too quickly while the car is off, that means the battery is fucked.

I've been through several batteries, had a few electrical gremlins for a while after I got my car, but since they have magically vanished.

_________________
S13 Silvia Tuning - The Definitive SR20 Modifying Site

I have gone through 2 alternators on my car...

Mostly the car sits at around 13 -> 14 volts....

Your car sounds like what mine does shpeedie... I could instantly tell when my alternator was on its way out because the voltage would increase to about 16 or 17 volts and this caused my stereo to shutdown (in order to protect itself).

_________________
Co-Founder, President & Webmaster
mayhem@silviansw.com - www.silviansw.com
Why drive when you can drift?

Out of interest how much are replacement alternators? And did you get an upgraded one in terms of amps?

_________________
S13 Silvia Tuning - The Definitive SR20 Modifying Site

Nothing when you have a spare motor in your garage

I have a CA18DE in my car and a CA18DET in the garage

I think they are around the $150 mark or less... no idea really, but that is second hand.

I didn't upgrade because its not necessary or useful until I have the SR20DET (S14) in the car

_________________
Co-Founder, President & Webmaster
mayhem@silviansw.com - www.silviansw.com
Why drive when you can drift?

hmm ok . .well i have NEVER exceeded 14 volts ..
but as snezy knows .. my car dies about 5-10 mins after i have the car off with the radio on .. its a shitty small battery so my cooler could fit in ..

so all i need to know is that something aint right if it doesnt run 14 volts the whole time !! Thanx

Your voltage will change depending how much current you are using IE radio, lights and at what revs your car is running at BUT 10-15 mins before your battery is stuffed is WRONG first of all check the water level in your battery if it is low top up with distilled water if not it sounds like your altenator

_________________
There is a very fine line between "hobby" and "mental illness."

where are you getting these reading from ? are you getting them at the battery or back of the altenator it could just be a case of poor wiring to you battery from the altenator... basiclly overtime the wiring get a resistance from the current flow... and this will cause a voltage drop to the battery... buying a second hand altenator isnt worth it.... you dont know what your getting in the terms of age and wear.... getting it recondioned would be my bet... you will get the things that wear out replaced..... take it to a auto elec they will tell you what the problem is..... if any.....

I agree with Koss but first of all check the water level as this is important a to how much charge it will hold and top up if needed and after running the car feel your battery terminals for heat you shouldnt be able to feel any except some from the motor if one of the leads is hot you have a bad connection so take of youe battery clamps and clean them and the terminals up and replace leads you are best of using bi-carb soda and hot water to clean with and once replaced put some vasoline on them to prevent it happening again and while you are doing this you can also add another earth lead from battery to the chassis people have reported gaining power from this but this is debatable

_________________
There is a very fine line between "hobby" and "mental illness."

When my last battery was fucked it was only one of the cells that was gone. Would drain to about 10.8 volts after engine off and parked. Took it to an autoelectrician and he took off the cell caps. The fucked one was smoking, new battery time.

Simple test, idle the car with the battery caps off, if any cells fizz or steam the battery is gone.

_________________
S13 Silvia Tuning - The Definitive SR20 Modifying Site