fluctuating voltage on a 2010 montero

[altec]

just came from mitsu casa. Using an analog tester, the readings came out to 13.5 without load, and 12.7 with load. We checked out the service manager's strada, his ride came to 13.8-14v. Then we removed the Strada's N70 Motolite battery and installed it to my Montero. Readings were still 12.7-13.5. We then looked for another Montero, with the original n50 GS battery. The readings were similar to the Strada's. Eto pa rin hirit ng service manager-- di siya naniniwala sa accuracy ng analog tester, but he will request from the mitsu plant in manila (sa sta rosa ba yun?) for a service alternator. Hopefully, that service unit will be delivered within the week and they will install it in my unit. Ayun, iniwan ko sa casa yung unit to wait for the service alternator.

[miked]

Ayun, iniwan ko sa casa yung unit to wait for the service alternator.

inakupow. sana wag lang nila gawan ng panibagong sira para kumita. heads up lang.

[altec]

Oo nga no? Pull out ko yung kotse bukas. Ipasok ko na lang pag dumating ang service alternator. Thanks for the heads up, Miked!

[miko101130]

Yep... Kakatawa naman yung SA... Pinipilit niya talaga yung baluktot niyang paniniwala at reasoning...12.7 volts is not normal with standard oem load..
If me technical manual sila, meron yang factory spec of what the alternator readings should be.... Analog tester or digital tester are fairly accurate..

Hahaha... Galing talaga ng s.a,, pag papa warranty client dame dahilan,,,
Onga sir, pull out mo muna habang wala pa service alternator,, baka ma-hocus pocus yan.. Hihihi...

[light2light]

sa battery charging, mas accurate kung alam mo ang charging current. may voltage reading ka na, dapat may ammeter ka pa.
i dont know why most cars do not have ammeters. basing your readings on both voltage and current is the surest way to analyse
battery problems. 3 cents worth lang po.

[miked]

the starter motor is the greatest power consuming device on a car. say a 2 hp starter motor will draw about 120-200 amperes. common automotive ammeters have usually a maximum reading of 100 A. usual gage have 60 A. thus the gage will blow out. afaik, ampere gages used on cars have a wire wired in parallel to the ampere gage to prevent this. exception are the alternator and starter testers used by auto and battery shops.

so my say is the voltmeter is better than the ammeter to check for a no-charge or overcharging condition. ammeters are way cheaper than voltmeters thats why most mechanics around the block use it for cars

[yapoy86]

you dont have to connect modern amp meters in series... you just need to clamp them on one supply wire.. the current creates a magnetic field that will be detected by the amp meter...

12.7 volts is low... i suspect your alternator IC is busted... volt reading with load should be at 13.5 volts minimum.. without load should be at 14.5 volts max...

if will have it DIY, i will change the Alternator IC first!! before changing the whole alternator...

[altec]

Update ko lang.

After so many back and forth with the service manager, nakisawsaw na nga rin yung president ng parts and service nila, initially the said they will request for a service alternator from the plant. But after waiting for over 1 week, nung follow up, sabi nila, wala, kasi nga walang problema. Using the casa's digital volt meter, we looked around and tested a 2010 gls 4x2 and a 2009 gls 4x4. The result? Both units' voltage also dropped to 13 and going down. Conclusion? Ganun talaga ang alternator ng 2010 montero. Even though sinabi ko sa kanila na sa kaibigan kong 2010 unit, hindi bumaba, yung sa dalawa kong kaibigan na naka 2012 gtv, plus 2 other 2011 units that we tested 2 weeks back using the analog tester na nag steady yung voltage readings nila, they still used the 2 latest montero units' readings as basis to say that the voltage drop is normal for the montero.

Yung assurance nila sa akin is that they have put the voltage drop on my unit's service record just in case may problema talaga at masira for the remaining warranty period. I just pulled out the unit na lang. I sent it to my company's truck motorpool as suggested by my suki accessory shop for voltage drop readings. Yung gagawin, kukunin ng voltage readings at saan na electrical load magstart yung significant drop. Then when that is determined, at lowest idling rpm, continue the voltage reading at 5 minute interval up to 1 hour to determine if the voltage will eventually stabilize or continue to drop below 12.


Iaano ko naman ang remaining warranty ng ride ko kung di ko naman ma claim sa casa warranty kasi para sa kanila, normal lang daw. (paano nga na promote yung service manager at yung president ng service and parts na parang kulang sa technical expertise yung dalawa, IMO) Ipapaayos ko na lang sa labas.

I will use that reading and submit it to my suki repair shop. Yung may ari ng repair shop, kinausap ko na rin. Sabi niya, he will check the IC, diode, stator, rotor. If IC or diode, pwede palitan. Pero kung may rewinding daw gagawin, he would rather look for a replacement alternator. For him, any drop to below 13 is never normal, maski anong sabihin ng mitsu casa. Yung dalawang montero na nag drop din ang voltage, most probably sira na rin ang alternator nila, di pa lang napansin ng may ari.

Which means baka at least up to the 2010 montero, hindi matibay ang alternator nila. I can't say with the 2011 and 2012 kasi yung apat na 2011-2012 montero na testing ko, ok pa ang voltage readings nila.

[yapoy86]

below 13volts is too low when the engine is running..... even car stereos are rated to operate at 13.8Volts!!!

when you turn off your engine, there is a "normal" voltage drop to around 12.9volts and it should hold there... when you start your engine you should have 14 volts reading then slowly stabilizing to 13.8 volts..

[altec]

eto ang results sa readings na pinagawa ko, bumaba hanggang 12.5v then nag hold doon. This was on a steady idling rpm of 650. Kasi pag nag switch on ang aircon compressor, the idling rpm goes up to 800-850, and the voltage readings goes up to 13. Pag nag rev, tsaka pa lang aakyat to 13.5 or so. I will take this up with my suki repair shop on monday.