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Thread: Alternator problem, please help Reply to Thread
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Topic Review (Newest First)
02-17-2013 12:58 PM
Capt. Obvious!
Originally Posted by mikeeshaq View Post
Capt. Obvious:
Where are you getting that F601 voltage regulator from? Just a name then I can search for details.
I'm getting the F600 style. The F601 style is what they have stock, these require the signal from the PCM where the F600 does not. You can just google "F600 voltage regulator" to find more info

This is the one I ordered

It is basically a really heavy duty version of the F600, You can find them cheaper if you shop around, but this company helped me find the info I was looking for so I bought from them.

Be aware that this is a rare problem, and the solution I provided requires custom wiring so it's probably a good idea to make sure that this is really what you need. The dealer I took my car to in order to get the PCM diagnosed said this is only the second Focus PCM they have ever seen fail and they've been around since well before the Focus was ever thought of.

99.9% of the time if you are having a similar problem, it is the result of the PCM connector going to the alternator/regulator. Wires in these are notorious for breaking. Some alternators even came with a new pigtail at one time.

I would suggest looking into this first.
02-17-2013 10:35 AM
mikeeshaq Capt. Obvious:
Where are you getting that F601 voltage regulator from? Just a name then I can search for details.
02-17-2013 05:46 AM
Capt. Obvious! Well, I found the problem. The PCM is not giving the voltage regulator the right signal. On top of that the alternator is also no good. Fortunately I found a solution that does not require the PCM being replaced.

First, I will be returning the bad alternator for a replacement. Then I will be replacing the stock F601 voltage regulator in the new alternator with a F600 type regulator. this regulator does not need the PCM to control it. It uses a 14.8v constant set point and only requires a wire that is hot with the ignition on and a sensing wire going to the output terminal of the alternator. I also bought a pigtail for the wiring harness to plug into the regulator so I don't have to cut up my factory harness.
02-11-2013 03:57 PM
Capt. Obvious! I checked the continuity of all the wires between the plug at the alternator and the plug at the PCM and the battery junction box. All were very good (0.1 k ohm). I'm going to tear apart the extra alternator I have to see if I can find a fault internally. Might have to make some sort of rig to test it. Also going to try to get into a dealer and see if I can at least get a diagnosis.
02-10-2013 11:07 AM
BC_ZX3 I'd be looking at continuity of the grey wire, in particular. The problem would seem to be somewhere in your wiring harness. Have you tried using a temporary duplicate wire i.e. wired up something outside the factory harness?

P1246 - Generator Load Input Failed
The PCM monitors generator load from the generator/regulator in the form of frequency. The frequency range is determined by the temperature of the voltage regulator where 97% represents full load, below 6% means no load.
Generator circuit short to GND
Generator circuit short to PWR
Generator circuit open
Generator drive mechanism
Damaged generator/regulator assembly
Damaged PCM
Verify battery voltage is 14.5V.
Verify generator/regulator has the correct part number.
02-10-2013 07:35 AM
Originally Posted by Capt. Obvious! View Post
Thanks for the info. It left me a little confused though, I was under the impression that only the European cars had the "smart charge" feature, mine is US spec. Am I missing something?
Ford builds their cars through out this planet
My Transit Connect is made in Turkey, with a Spanish built engine and an American made transmission. The radio is made in Portugal
US Spec refers to EPA and US Highway transportation requirements.

Pulse Width Modulation is used because it is just 'switching' and there isn't alot of heat generated with respect with trying to control the alternator via an analog signal

OH yes what went to the moon had far less computing power than today's modern automobiles
02-10-2013 03:47 AM
Capt. Obvious! NEW INFO
I put the SCT flasher unit on it and tested for trouble codes (even though the CEL is off) and it came up with a P1246 - Generator Load Input Failed (All Others) It was at this point I realized that the CEL should probably be on as well as the Battery light. They do however come on initially when I start the car, and the battery light comes on if I unplug the voltage regulator. I don't know what to make of this, but it seems like it probably has something to do with my problem.

Originally Posted by BC_ZX3 View Post
You haven't mentioned checking the charging circuit fuse - fuse 10 - but I'll put it out there anyway.
Yeah, that was the first thing I checked when I realized the alternator didn't fix it. Without it I wouldn't be getting the power on the red wire. I would order the rebuild kit as you suggested but I really don't think it would help. I've replaced the alternator twice in the past week with new alternators from different companies and the symptoms have remained the same.
Originally Posted by mikeeshaq View Post
See link:
It explains the Pulse Width Modulation for Ford alternators
and another:

Thanks for the info. It left me a little confused though, I was under the impression that only the European cars had the "smart charge" feature, mine is US spec. Am I missing something?
02-09-2013 10:50 PM
mikeeshaq See link:
It explains the Pulse Width Modulation for Ford alternators

and another:
02-09-2013 08:30 PM
Originally Posted by Capt. Obvious! View Post
I have the pin-out, (pin 72 and 59) I don't know for sure what the voltage should be. I read somewhere it should be battery voltage on the red wire, 9v on one of the others (blue iirc) and zero on the last one (which I have). But I cant find where I read it again.
You haven't mentioned checking the charging circuit fuse - fuse 10 - but I'll put it out there anyway.

A description of the connector's wire functions from Ford:

"Circuit Description

Battery Output Terminal (B+) Circuit 30-BA6 (RED)
The generator output is supplied through the battery positive output (B+) terminal on the rear of the generator to the battery and electrical system.

A Circuit 30-BA10 (RED)
The A circuit is used to sense battery voltage. This circuit is also used to supply current to the generator field (rotor) and to turn on the voltage regulator which determines generator output. It is also used to turn the charging system warning indicator on if there is a fault in the charging system operation.

Circuit 5-EB6 (BLUE)
This is the generator communication (GEN COM) circuit. The PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator via the GEN COM circuit.

Circuit 4-EB6 (GREY)
The generator monitor (GEN MON) circuit communicates the generator load and error conditions to the PCM."

I'd be replacing the PCM as a last resort; the rebuild kit you referenced wil be cheaper and easier to try first and an intermittent or faulty VR is more likely. (btw, the above wire colours reference the 2003 model year - the Duratec cars were wired a bit differently and a big 175A fusible link was added to the battery output circuit.)

If you need the diagnostic procedure/pinpoint test mentioned earlier, pm me. It's not that helpful in your odd situation though; once you isolate the alternator as the source of a problem, the instructions are to simply replace it. Ford considers it a non-serviceable sealed unit so it doesn't go into any detail about VR testing.
02-09-2013 04:19 PM
mikeeshaq I think the alternator control works on PWM pulse width modulation. When there is a demand for current then the pulses are wide. When the demand is low, then the pulses are narrow
Having said that, to replaced the ECM, you also need to program the PATS, so you need to go to Ford. Unless of course you find a ECM in a junker with a key
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