Voltage Problems

[kentb]

i just got an oil change about 2 months ago

[kentb]

what bugs me is that after i got to work my alternator was still working perfectly

then i got home, rest for a bit then went out again.

then the batt problems suddenly showed up

it was just a span of 3 hours with the car turned off.

[Jextel]

so i got:

optima yellowtop under the hood

kinetik hc2400 on the back

iraggi 240/165 amp alternator

it was running fine for about a week since i installed it,

my voltages were:

14.2@idle, 13.4v w/ engine off

this morning it was running fine too

so when i was leaving this afternoon, i noticed the battery gauge was pretty low

i checked the voltage and it was only 12.7 while the car is idling and system is off

so i turned my car off and checked the voltage, it was 12.8

so i disconnected my powerwire that runs to the back battery and the amps

after about half hour driving

i checked the voltage, while idle it was 12.3

when it was off it was 12.5

what do you guys think? did my alternator died?

i checked all the wire connections and it seems that its good

I had this problem with my second alt from iraggi but it only lasted less than one song im on my third and volts get as low as 11.7 just like my stock alt....im in the same boat as you im just ready to get another alternator from OG or EA

[Decaf]

this happens with HO alts, they produce alot of power once engaged, and dont turn on usually until under a load or at 800-1000rpm

so at idle, it should read 12.8ish, and with car off it should be right around there to

so test voltage when someone has the throttle enganged, it should read up to almost 15 volts at 2000+ rpm

that will let you know if its the alt because if its producing plenty of power once enganged the problem is that the regultator is off until a load is present... which techincally isnt a problem, more of an annoyance

ive rarely seen a battery sit at 13.4 unless it was on a charger on "float," remember they are 12v batts, so batts shouls sit from 12-12.9 since theres and extra .1 -.2v extra per cell produced

so ideally

car off bat should say 12.8

car on, at idle, should be low 13 if not still 12.8

throttle engaged should be 14.4ish

full tilt with throttle engaged at ~2000rpm should be above 13 with the upgrades u have

this happens with EA alts also

[Matt Young]

this happens with HO alts, they produce alot of power once engaged, and dont turn on usually until under a load or at 800-1000rpm

so at idle, it should read 12.8ish, and with car off it should be right around there to

so test voltage when someone has the throttle enganged, it should read up to almost 15 volts at 2000+ rpm

that will let you know if its the alt because if its producing plenty of power once enganged the problem is that the regultator is off until a load is present... which techincally isnt a problem, more of an annoyance

ive rarely seen a battery sit at 13.4 unless it was on a charger on "float," remember they are 12v batts, so batts shouls sit from 12-12.9 since theres and extra .1 -.2v extra per cell produced

so ideally

car off bat should say 12.8

car on, at idle, should be low 13 if not still 12.8

throttle engaged should be 14.4ish

full tilt with throttle engaged at ~2000rpm should be above 13 with the upgrades u have

this happens with EA alts also

The above description is pretty correct. The main reason why the voltae is low at idle. is because at that RPM a high output alternator usually doesn't put out much amperage. Bring the RPMs on the motor up and see if the voltage comes up.

You can tell if the belt is slipping by carefully feeling the temerature of the alternator pulley after the vehicle has been running for a while under a heavy electrical load. If the alternator pulley is noticibly hotter than the rest of the alternator, or if it looks discollored or black on the belt contact area, you have a belt slip problem.

Changing the oil has ABSOLUTELY nothing to do with an alternator or belt slip problem.

[kentb]

tried that too

when i rev it up it actually drops about .01-.04 volts

im gonna bring it up to a mechanic today. i hope my alternator is still good

i noticed that my battery is not charging, everytime i check the voltage it slowly goes down.

[missinglink]

tried that too

when i rev it up it actually drops about .01-.04 volts

im gonna bring it up to a mechanic today. i hope my alternator is still good

i noticed that my battery is not charging, everytime i check the voltage it slowly goes down.

Your alternator is not charging. A drop in voltage from resting to running indicates that you are taking power from the battery, not charging it at all.

You could have a bad regulator, failed brush, broken wire, a couple of open diodes... The list of possible failures is long.

I doubt you have a belt tension issue if you have a serpentine belt with the OEM tensioner.

Some alternators have a self-test capacity. Is this a Ford alternator?

'Link

[kentb]

the mechanic said the alternator was bad. i got a new one from autozone and got it installed, it worked perfectly no problems at all. it even fixed my battery light indicator which lighted up all the time the iraggi alt was in.

i talked to iraggi he seemed like a nice guy, im send it back to him, i hope everything is good.

does anyone know if i can put 2 alts in my explorer?

[cichlidfort]

Take a picture your engine and post it.

[mrrairai]

I guess I'm late but I was gonna say that your alt is bad. I had that same problem a few years back with the same symptoms on my Expedition. Glad you got in contact so you can get it taken care of. I always keep my stock alt handy just in case tho.