Bad Alt.?

Hi guys, recently i was checking my Ohio Alt. and i saw that sometimes at idle the voltage with load and no load is like 12.3 volt and sometimes it is 14.4. then sometimes when the eingine is at idle the voltage is like 13.5- 13.7V and when the rpm goes up above 2000 rpm the voltage stay the same it doesn't go to 14.4 volt but sometimes above 2000 rpm it does go 14.4V, so does i have a bad Ohio? or maybe because the battery(cheap one for the moment) that i have is causing the regulator to be instable? anyways thnx, Aruman.

-------------
Shaking The Neighborhood

Most likely different loads on the alt at the time.  To test like this, you have to have total control of what system in the car is demanding current at the time.

-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

First check you battery. Put your meter on the battery and start you car. The voltage should not drop below 10.5v at any time. Next, if you have access to a battery charger, charge the battery at the highest amperage setting on the charger and the battery should never go above 15v. If it fails either of these, then you have a bad battery.

Next, use you meter at the battery and put a large load on the stsyem  (turn on hi-beams, blower for heater, ect..). Do not turn on stereo or any other electrical compontent that the load varies (blinker, hazard lights). At idle, your voltage should stay above 13v. If it drops below 12.5v, you may have a bad regulator. When you run up your RPM's, the voltage should climb to around 14v. If it ever goes above 14.8v or so, you may have bad diodes in the alternator. If it is border line on any of these test, just keep a eye on the system. But it is always reccomended to upgrade the "Big three" no matter what and check all of you battery connections. 80% of electrical system problems are caused by bad connections.

-------------
2003 GMC Yukon, Kenwood 815DVD w/ Nav. Memphis speakers. Kenwood 1200W Amp, Alpine 400W amp. Rear view camera, headrest monitors. Parrot CK3100

Thanks guys,

I think i have a bad regulator, cause i've done that test you mention elicoleman, but i tested it only with the Hi-beams and the fog -lights, when the Hi-beams and the fog-lights are on i get like 12.3- 12.4 volt with the stereo off and on but at volume 0. this is sometimes, because sometimes it just works fine and get the 14.4V. The reason number one that i think my Alt. is bad is that when my car is at idle the volt is like 13.5- 13.7 volt and when i run up the rpm the volt goes up to 14.4 volt, but sometimes it didn't goes up to 14.4volt, i've tested it with stereo on and stereo off and with both i get the same problem. that some day it goes up to 14.4 volt and some day not.
I will contact Ohio and see what i can do. or maybe i check if i can fit an bigger Alt. maybe the larger GM based CS-144 does anyone know big(amperes) Ohio makes of this model? thanks, Aruman.

-------------
Shaking The Neighborhood

Before you write off you alternator, make sure you do the battery test and double check your connections. If they all check out, then oull the alternator and take it to any parts store and have them run a bench test. I used to be a mechanic, and I can't tell you how many times someone thought they had a bad alternator and replaced it, then brought it to me because it was having the same problem.

-------------
2003 GMC Yukon, Kenwood 815DVD w/ Nav. Memphis speakers. Kenwood 1200W Amp, Alpine 400W amp. Rear view camera, headrest monitors. Parrot CK3100

One other thing I would check is your voltage regulator.  Depending on your vehicle theyre about $35 and you can install one in about 3 minutes...

-------------
'89 Mercedes-Benz 300E
Pioneer DEH-5900UB
(2)RE Audio SX 10"s
(1)US Amps MD3D
3ft^3 @ 37Hz

Blowing up in a car accident doesnt worry me, as long as I'm putting out some major dB's when I die...