BAttery ?

[Jamrud]

hallo, i experience problems wif my volt meter..im driving an Auto transmission car..When i start the car, gear in P position, the meer will show voltage ard 11..but when i put gear in D or R position, the meter will drop all the way down t 8. how come eh? must change battery ??

 

[mie4385]

better ask your trusted mechanic to check your car....maybe your alternator...sometimes battery also play a part...but better safe than sorry...

 

[khguan]

where u tap ur de voltage for ur voltmeter??

 

[huakenny]

juz happen or very long liao..?

 

[Jamrud]

quite sumtime oredi.. FYI, i go to my mekanik ,he checked and said my batt and alternator is in good condition. The old voltmeter, i replaced with a new one , but oso same lehhh..when put to D gear, it went to 8

 

[simefly]

Then it should be your alternator... It is not generating enough hence the short of power occurs... maybe you should tryout the combination of switching on the headlights while in P then move to D or even switching on your aircon to the max and move from P to D

If the voltage drop, then the alternator is healthy but not that compatible...

 

[kage2099]

Jamrud... i think its relatively normal... my car oso liddat... when idling the volt shows 14V... but when engage the aircond, sound system and shift to D... the volt drops to 12V... funny thing happens is when i drive... when i drive, the volt will go back to 14V... im very certain my battery is well and running (cuz juz changed it) and the alternator is fine too (cuz mechanic juz checked)... so... im pretty sure its normal...

but... i do realize ur voltage is abit low... 8V... im not sure but it sounds low to me... but then again i do have a DIY VS and groundings done lah... im not sure those DIYs will show any changes...

 

[mie4385]

from my xp lah...when ur ignition is on the meter shows 12v...when idle it shows around 14v..this is normal condition for your car with battery and alt ok...but if when battery is about to kong,at on it will show below than 12v....but if your alt is kong...at idle it will go below 12v even when you rev ur engine...just my 2 sens...but correct me if i'm wrong....

 

[huakenny]

u try to use ur fren battery in ur car n see wat is d volt reading....if after change batteery oso no different....then maybe ur alternator hv to service...my 2 cents

 

[simefly]

usually the OEM alternator capacity is not really that great to begin with. It is usually normal that the voltage will drop from idling to D (remember D = 1st gear + foot brakes is on... Its like releasing your clutch alil but your other foot is still on the brakes) But, once you have release the foot brake, you will notice that the rev will be back to normal.

So this is perfectly normal... VS will help in a slightest way... even changing the alternator wont help much...

 

[phat7]

your safe crancking start voltage has to be greater than 11.4V so looks like you're quite safe. I would look at the stepper motor to see if its discharging correctly or have a closer look at the alternator. The alternator has three diodes. I have seen cases if new cars burning at least one diode within a year of purchase. Good luck