Battery or alternator problem (Pajero 4d56)

**neil_xtrm** · August 2nd, 2009 10:06 AM

Need your help on this one..Yesterday i notice that my voltmeter drops when i turned on my AC from 13.5V down to almost 12V. I also tried turning on the headlight and off the AC and same thing happened. But when i drove it around charging when up to 13V to 13.5V and as i slow down it drops again. im not so sure if the problem is the battery or the alternator. My battery is new i just purchased it last January of this year.
Early this morning i tried it again and same thing happen, i tried pulling off the negative terminal to check if the problem is the alternator but its not the car still idles when the negative terminal is not connected.
My fellow tsikoters i need your help and advices on this one.
thanks in advance

**jick.cejoco** · August 2nd, 2009 11:26 AM

Originally Posted by neil_xtrm

Need your help on this one..Yesterday i notice that my voltmeter drops when i turned on my AC from 13.5V down to almost 12V. I also tried turning on the headlight and off the AC and same thing happened. But when i drove it around charging when up to 13V to 13.5V and as i slow down it drops again. im not so sure if the problem is the battery or the alternator. My battery is new i just purchased it last January of this year.
Early this morning i tried it again and same thing happen, i tried pulling off the negative terminal to check if the problem is the alternator but its not the car still idles when the negative terminal is not connected.
My fellow tsikoters i need your help and advices on this one.
thanks in advance

neil,
DO NOT DISCONNECT THE BATTERY NOR ANY ELECTRICAL COMPONENT WITH THE ENGINE RUNNING. there had been discussions on this before
jick

**bambino** · August 2nd, 2009 09:50 PM

the best way to check the charging systems of your vehicle is to get a multimeter and check it from the main batt terminals .

at least 14.5 v *idle ( no loads)

at least 14v *idle ( full loads)

don't disconnect the batt while the engine is running . that's a no no .

**neil_xtrm** · August 3rd, 2009 10:49 AM

Originally Posted by bambino

the best way to check the charging systems of your vehicle is to get a multimeter and check it from the main batt terminals .

at least 14.5 v *idle ( no loads) 13.8 V

at least 14v *idle ( full loads) going down to almost 12 V

don't disconnect the batt while the engine is running . that's a no no .

what happens if you disconnect the battery while the engine is running?

thanks for the advice....

**bambino** · August 3rd, 2009 11:24 AM

the sudden surge of power coming from the alt is not healthy for your modules that may cause you more problems .

the readings you got , points to your alternator starting to go so you might as well get it checked by a qualified tech and get it rectified.

**innoBOB[09JmtG]** · August 3rd, 2009 11:34 AM

Originally Posted by neil_xtrm

what happens if you disconnect the battery while the engine is running?

thanks for the advice....

hehe, in case of emergency, this is a must!

done this once on an L300, naiwan ng sanpits ko ilaw, ayun nadisgarga..

e wala kami jumper cables, hiram kami batt sa honda city, tapos pag start, palit ung na diskargang battery

ginawa ko na din ito sa isang corolla na matic, na diskarga din, hiram batt ng beetle, balik orig batt.. hehe

**neil_xtrm** · August 3rd, 2009 05:45 PM

Originally Posted by bambino

the sudden surge of power coming from the alt is not healthy for your modules that may cause you more problems .

the readings you got , points to your alternator starting to go so you might as well get it checked by a qualified tech and get it rectified.

thanks for the advice....

**bambino** · August 4th, 2009 06:43 AM

You're welcome .

**neil_xtrm** · August 4th, 2009 11:06 AM

This morning i drop by the store where i purchase the battery and have them check the voltage drop and the result is the battery is ok the problem is my alternator which gives fluctuating results of the voltage drop when i load something ( ac and headlights)..so the Culprit is the diode which gives fluctuating voltage drops.
I'll have this check this weekend and update you guys on the results..
thanks for all your advices..

**nogz** · January 18th, 2010 12:43 PM

Originally Posted by neil_xtrm

This morning i drop by the store where i purchase the battery and have them check the voltage drop and the result is the battery is ok the problem is my alternator which gives fluctuating results of the voltage drop when i load something ( ac and headlights)..so the Culprit is the diode which gives fluctuating voltage drops.
I'll have this check this weekend and update you guys on the results..
thanks for all your advices..

I have the same problem with my civic. My battery light went off so I decided to just have my battery replaced since it's already been 3 years since I bought it. So I went to motolite cor. Dela Rosa and Pasong Tamo (next to obeertime) bought a new unit (they checked my old battery and it is already on the weak level on their gauge pero sabi pwede pa daw kaso anytime daw pwedeng mamatay na un since its already 3 years mula nung nabili ko sya) when they had it fixed the battery light is still on so when they checked the alternator hindi daw nag chcharge... I'll have their technician check it later (Alternator) I'll update all the tsikoters here para sa mga first time din na makaka experience nito e alam nyo ang pwedeng maging scenario ng ganito. Kasi ako first time ko to