Alternators ?

[FordNut]

Anybody had an issue with alternator failures? I had one about a month ago, had a new one put on under ESP, and now it seems to be dying again. Battery reads 12.2 v instead of 14 v with the car running. I guess I could see it if I was using a cheapo alternator, but this was a brand new one from Ford.

[MENINBLK]

Anybody had an issue with alternator failures? I had one about a month ago, had a new one put on under ESP, and now it seems to be dying again. Battery reads 12.2 v instead of 14 v with the car running. I guess I could see it if I was using a cheapo alternator, but this was a brand new one from Ford.

At idle or off idle ?
Are you also measuring it with the accessories on or off ?
Are you also measuring it from the fake VOLTMETER or a REAL Multimeter ?

At idle with NO ACCESSORIES on, it should read 12.5V or higher.
Most Alternators put out 13.8V - 14.5V.
If its less than 12V than you've got something to worry about.

My Fake VOLTMETER used to read 12.5V all the time.
My REAL VOLTMETER ranges from 12.5V - 14.5V depending on what accessories I'm running.

[cruzer]

Had the same problem--even had noise that sounded like an alternator bearing--sharp tech checked the BATTERY--it was causing all the trouble--new battery--15,000 miles---no trouble---have them do an extensive battery test--so it wouldn't hurt !!!

[FordNut]

At idle or off idle ?
Are you also measuring it with the accessories on or off ?
Are you also measuring it from the fake VOLTMETER or a REAL Multimeter ?

At idle with NO ACCESSORIES on, it should read 12.5V or higher.
Most Alternators put out 13.8V - 14.5V.
If its less than 12V than you've got something to worry about.

My Fake VOLTMETER used to read 12.5V all the time.
My REAL VOLTMETER ranges from 12.5V - 14.5V depending on what accessories I'm running.
Both.
Both.
The same Autometer one I've been using for over 2 years, verified with a Fluke.

It has always started and idled at 12v or so, then gone up to 14 when the revs increased. Now it usually just sits at 12v but occasionally drops to 11 when idling with accessories on. Never gets above 13v no matter how high the revs are, usually not over 12.5 or so. Old alternator acted similar, but intermittent. Replacement worked great for awhile, but now it does this and it's like this all the time instead of intermittent.

My OEM voltmeter read the same way my replacement does. 12v at idle, 14v as rpm increases. My OEM oil pressure gauge was a fake.

[FordNut]

Had the same problem--even had noise that sounded like an alternator bearing--sharp tech checked the BATTERY--it was causing all the trouble--new battery--15,000 miles---no trouble---have them do an extensive battery test--so it wouldn't hurt !!!
I'll try that. My battery was replaced with an Optima about a year ago so if it's bad I reckon it'll be a warranty replacement.

[drgnrdr33]

Mine's doing the same thing. I can't get over 13V no matter how many revs. About two weeks ago I started noticing the gauge reporting lower voltage than I remember before. I verified tonight with a real DMM that my voltmeter matches my DMM. 6 months ago I was working on another car project and at the time the voltage at ilde was 14.1 to 14.4V on both meter and DMM.

Today in traffic it dropped to about 10V for a little while then went back up to 12.8V. Time for another dealer trip.....


Both.
Both.
The same Autometer one I've been using for over 2 years, verified with a Fluke.

It has always started and idled at 12v or so, then gone up to 14 when the revs increased. Now it usually just sits at 12v but occasionally drops to 11 when idling with accessories on. Never gets above 13v no matter how high the revs are, usually not over 12.5 or so. Old alternator acted similar, but intermittent. Replacement worked great for awhile, but now it does this and it's like this all the time instead of intermittent.

My OEM voltmeter read the same way my replacement does. 12v at idle, 14v as rpm increases. My OEM oil pressure gauge was a fake.

[Rkammer]

It reads the same as a calibrated test gauge if the voltage is measured at the same place as the OEM gauge. The interior gauge will almost always read 1/2 to 3/4 of a volt lower than the actual voltage at the alternator terminal because of the voltage drop between the alternator and the interior wire where the voltrage is read. I had this same issue with my last car (an Olds Touring Sedan) and bugged the dealer numerous times until I found out that it was the same on all of those model cars.

So, if the interior gauge reads only 13 volts or so, the actual voltage at the alternator is probably 13.5 to 14. The more accessories that are on, the greater the difference will be between interior gauge and actual voltage. :)

[rumble]

I guess I could see it if I was using a cheapo alternator, but this was a brand new one from Ford.


You bring up a very interesting point, as expensive as this
alternator is does any one know of an aftermarket source for
our up coming "out of warranty situations"?

[RF Overlord]

I agree with Rkammer...the stock voltmeter is not fake...mine has always read somewhat higher with higher revs than at idle, and it seems to track the load as well...it goes down quite a bit if I actuate a window while sitting at a stoplight with the headlights on, etc...the replacement AutoMeter gauge (done only for cosmetic reasons) works exactly the same way.

[WolfeBros]

The voltmeter is not a fake. I bench tested mine with a power supply and digital voltmeter when I had the whole panel out to replace the real fake ......the Oil pressure guage. The OEM voltmeter tracked fine.

[cruzer]

Had the same problem, 2 hours of trouble shooting and a replacement battery solved the problem 20,000 mile ago--some sor of weird internal failure--it worked for me