alternator problem

[datmbn]

The problem is that the alternator at some uneven intervals charges over 16 volts for a second and then returns to the correct value again.
I discovered the problem because my androidstereo restarted seemingly unmotivated.
I then connected a voltmeter so I could monitor the system, and you see that it behaves completely as expected (maybe a tenth of high voltage)
to suddenly give 16+ volts in a second maybe once a week or two times in an hour.
Does anyone know what can cause this.
regards Mats

 

[s8v4o]

Voltage regulator

 

[07 Boss]

Voltage regulator

Do we have a voltage regulator? I always though that was controlled by the ECU.

 

[datmbn]

There is a 3-wire charging regulator 1+, 1com and 1mon And I think it work like this:
If you connect com to earth, it works as a regular regulator and gives about 14 V
ECU controls the voltage by pulse voltage on this port so that the controller does not measure between + and ground, but between + and an increased value.
The mon port is used as back-up so that the ECU knows what the regulator is doing is doing

 

[redfirepearlgt]

Voltage regulation is done within the alternator. The days of separate voltage regulators in Fords ended decades ago.

The PCM actually monitors the voltage regulator in the alternator and regulates it accordingly. (see charging section diagnostics in the Ford tech manual) In addition to this there is also (on some models) a one way clutch that will disable under WOT loads separating the alternator form the drive system allowing free spin. This is supposed to reduce belt issues and lengthen the life of the alternator.

The PCM also monitors the IAT and uses that to make voltage corrections for the battery as battery properties change with temperature. I was not aware of this but it makes perfectly good sense. A nice thing to know.

End result is that it sounds like your alternator is failing. You may wish to have the battery checked under load before replacing the unit, but it is possible that if the system has been overcharging, the battery could be an innocent victim as well.

Below is a link to diagnostics for the charging system.
http://iihs.net/fsm/?d=361&f=Charging System.pdf

 

[bl817]

If you end up needing an alternator, get one for the 2010 model in auto or manual transmission, whichever applies. good luck

 

[Pentalab]

Bruce H posted a screen shot of what the voltage is... vs ( I think) ambient temp, IAT, CHT, and a few other parameters. It was not much of a variation, like anywhere from 14.25 vdc, all the way up to 14.60 vdc.

My guess is the built in internal regulator is crapping out. When you vary eng rpm from idle... up to rev limit, the min / max rpm of the alternator is now aprx a 1:10 ratio.... hence the obvious requirement for a regulator....and also the built in clutch assy, to let the alternator free wheel, out of the circuit, at wot. I forget what the diam of the alternator pulley is, but it obviously way smaller than the aprx 6.6" crank pulley on the eng. The alternator is spinning at least double the eng rpm.

16 + vdc could eventually fry the poor battery. It could also fry several other items. In normal operation, with 14.4 vdc, the battery will be happy with the 14.4 vdc for hrs on end, like a long drive.

If you have to replace the alternator, use the oem one from the 2010, it basically drops right into place, rated at 135 A. You might also have another issue with the oem alternator, like a failed / shorted diode in there. In which case you end up with AC ripple on the output. batteries don't like AC ripple. Switch your DVM to indicate AC volts..and see if you measure any AC ripple.

 

[datmbn]

It is hard to measure anny fault because it works good except for 1sec every 2 days.
So all voltagemesures and AC ripples (0.3 V) are good to.
But you are probably right that it is time to change the alternator

Regards Mats

 

[Pentalab]

.3 / 14.0 = 2.1% ripple.... which is dick really.

Something is amiss with the alternator. It should be rock solid at aprx 14.4 vdc... idle or way higher rpm. Yours is all over the map. That plus ur occasional 16+ vdc condition.

You might want to start with a good known alternator. Make sure the new alternator setup is rock solid, then re-test the rest of it for FPDC, wandering idle etc, etc.

 

[07gts197]

I recently went through this with my 98 vic. On really cold mornings (well cold for florida lol) I would start it and only the exterior lights worked and the transmission acted funny. None of the interior lights worked, the headlights would flicker, gauges didnt light up and no rear defroster. Imagine driving like this in pitch black... then after a few miles a click from the circuit breaker could be heard and just like that everything came back.

Well one day I got curious and decided to datalog when it happened. It was charging over 16 volts! Luckily I had my 02 gt sitting at the time so I swapped alternators and all was good.

So I would have to agree it sounds like the alternator is going.

 

[datmbn]

Ordered a new Remy brand from Rockauto for $ 142 ink shipping.
I chose Remy because it's the same as Delco and I have a good experience of it (I sit one on my Citroen C6 that has gone over 300,000 km)
In the meantime, until the new generator comes, I hanged a voltage protector over the battery terminals.
It actually seems that the voltage protector stabilizes the generator, so it's very likely that it spreads AC spikes = diodes on its way to break.

 

[s8v4o]

Lots of people have problems with aftermarket with this particular alternator, even Remy. I ended using an 06 crown vic police interceptor 215AMP. Only needed very little modification to fit. It's still working great 4 years later. Hopefully you won't have problems with the Remy.

 

[datmbn]

Yesterday the new generator arrived (had to pay customs duty so prices were about 170 $ total)
Seems to work well, is stable at 14.1-14.2 volts
So, so far so good just hoop it stays that Way

 

[Michael Zeda]

I have the exact same issue. I got the code for the sensor that pops up on these cars that is actually the alternator . so I bought a reman from advanced auto.
Immediately after the alt change when I get on it at lower speeds my radio would shut off. at first I didnt look at the dummy voltage gauge but after it happened many more times always at wot and also throwing off my ABS warning lights I decided to datalog it. it showed I was going up to 15.96 volts.

SO now I am trying to find a solution other than changing out 15 alternators in a row.

 

[Pentalab]

Get the oem alternator used on the 2010 mustang. It's the best of the bunch..and the most reliable.

 

[Michael Zeda]

Get the oem alternator used on the 2010 mustang. It's the best of the bunch..and the most reliable.

I did check on those. but I found a remy 12622 crown vic alt for $119 on ebay so I grabbed it for now. the prices on the 2010 were as much as the ones from DOB and at the moment I cant spend another $300+ when I still have to contend with the 1 month old alt in the car.

when I get the remy alt I will remove the current alt and take it back and get replacement. then sell it cheap and move on. the remy 12622 was on the police vic so and what I have read is a better alt. so couldnt pass on it.

I love my mustang but damn Ford makes me want a G35 again for all the idiotic stuff.

 

[406guy]

I did check on those. but I found a remy 12622 crown vic alt for $119 on ebay so I grabbed it for now. the prices on the 2010 were as much as the ones from DOB and at the moment I cant spend another $300+ when I still have to contend with the 1 month old alt in the car.

when I get the remy alt I will remove the current alt and take it back and get replacement. then sell it cheap and move on. the remy 12622 was on the police vic so and what I have read is a better alt. so couldnt pass on it.

I love my mustang but damn Ford makes me want a G35 again for all the idiotic stuff.

What is the part number of the 2010+ alternator?

 

[Michael Zeda]

What is the part number of the 2010+ alternator?

I dont know. I just looked up the alts at my local advanced auto.

the 12622 is a nice alternator that is working just fine in my car now. cost was 119 plus shipping.

 

[1950StangJump$]

What is the part number of the 2010+ alternator?

If you're interested in going with the Remy 12622, PM me. I bought one new (reman) for my car, but it won't fit with my Kenne Bell setup. It is 215 amp. Will cut you a deal.