Battery or alternator problem (Pajero 4d56)

[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

[jick.cejoco]

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]

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]

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]

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]]

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]

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]

You're welcome .

[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..

[nogz]

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

[anthon05]

hello.. you said on idle when you turned on the AC the voltage drops
and if you go around it will pick up again. try if you just step on the gas pedal
and see if it reaches at least 13.5volts with or without AC. baka mababa lang

rpm mo. or wala na sa kondisyon yung alternator. advice ko have your alternator

cleaned lang and replaced bearings etc.. if diode ang problem ( yan naman sasabihin ng lahat ng electrical shop) mahal yun almost cost of the entire alternator. just try to rev it or step on the gas while parked observe mo kung

tumataas voltage, kung tumataas it means kumakarga.

[paulgozon]

Your problem is simple and difficult to diagnose (because its on the borderline), it can be a loose belt, loose connector of the battery or alternator. Try tightening the belt, check with a digital voltmeter connector to the battery, if the a/c on, the voltage should be above 13.0 volts. If nothing happens, try wiggling the connector on the battery post and on the alternator, if nothing happens, the problem could be inside the alternator (brush, diode, regulator, winding, bearing)

(here is my tip when working with electricals/electronic, check, recheck, and check)

[neil_xtrm]

its been a while since i have'nt updated you 'bout this tread...i already have my alternator check and the problem was the diode...there are 4 diodes in there and one of it was broken so the technician advice either to replace the broken diode or replace the whole thing...since my alternator is quite old already i decided to replace the whole rectifier diode...
Now the problem is gone...
thanks for all your advises....

[intel_1nsid3]

My bro bago lang po ako dto.ask lang sana ako advice about my problem below.

lastweek, nadiskarga yung battery ng pajero ko so i called motolite to deliver me a new battery. so when the delivery man arived and installed my new battery, umandar n yung pajero ko. but when he checks my charging, when idle, umaabot sa 16V ang karga then drop to 14.5 when lights on and AC.
Then yesterday, noong paandarin kona ulit yung pajero ko, ayaw na ulit umandar, then i checked again d battery its lobat. so i jumpstarted it with my friends car then it started. noong chineck ko uli yung battery ko if nagchacharge, it shows that the battery is not charging co'z even if i rev my car, the output is still 12V. so i drove my car into shop, to let my alternator be fixed. But when the mechanic checked if the alternator is charging, the tester shows that its ok daw naman kxe kumakarga. so they dint do anything kxe ok daw naman.
but this morning when i chaked again nde nanaman sya kumakarga.and i called a mechanic sabi nya yung crankshft pulley daw my tama kaya daw my time na kumakarga sya at my time na hindi rin kumakarga.
need ur advice mga bro if do ineed to replace my pulley or alternator. thanks