Hello everyone I'm new to this site and of course because i have charging problem. I will start with the truck.2001 f350 powerstroke 7.3ltr diesel auto.

my battery light came on and of course thought it was my alternator, so i put a multimetre on it and it said it was not charging and i also checked allmy fuses, they seem to be all good. so i go and buy a new alt and install it, the light still stays on. so begin to check all the grounds on the motor,frame,body,etc all are seem to be good.I phone ford and they say i might have got a dud alt. so i go back to the parts store to get another alt and on my way there the battery light goes out? and it starts charging again? so i go in the store and tell them the alt is no good and is only charging sometimes, so they give me another alt and i head home (20min away) on the way home the battery light comes back on?
so i install the second new alt and the battery light still stays on?? now i'm getting (pist). so i get a wiring diagram for my truck from a hanes repair manual, I have voltage at the orang/blue wire at alt, no voltage at green/red wire at alt. we do have voltage (11.9volts) on white/yellow on line side of instrument cluster/charge indicator. power is going into instrument cluster/charge indicator but none coming out?. where is the problem???

 

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No voltage coming out of the instrument cluster/charge indicator is how the Regulator turns the light on, it grounds the wire. If you had voltage on it the light would be off.
I do not have a print with the wire colors you named but if you would translate the wire colors to where they are connected I will try to help. Wire color connections would be "B+", "I", "A" and maybe "S’s" at the Alternator.

Do you have the 200 AMP Alternator?

 

is there any way i could fax you a copy of the wiring diagram that make it easy for me?
thanx for helping Rusty!!

 

ok i'll try to make this make sence! The red/black wire coming from the ignition goes to the central juntion box (fuse 29 5A) I have power coming out of junction box witch the wire color turns into white/yellow going into the insturment cluster.coming out of the instrument cluster the wire turns into green/red (with no power) , this wire goes to the alternator clip, witch i think should have power????
Hopefully this is right,thanks for helping!!!!!!!!!!!!!

 

If it is possible, disconnect the lightgreen/red wire from the alternator, and then start the truck and see if the light goes out.

If you can disconnect it right at the alternator, and the light stays on, then the lightgreen/red wire is touching something metal on the way to the instrument cluster.

If the light goes out when you disconnect the lightgreen/red from the alternator, then something is wrong with the alternator.

I am trying to think if there is anything that could go wrong with the rest of the alternator wiring, to make the light come on. I would just check it out to be sure. I see a fuse #6 in the fuse box under the hood that goes to the alternator, and you said you had 12 volts on the black/orange wire at the alternator correct? If so, that means the two fusible links must be good that go to the black/orange wires.

Also. with that fuse #6, make sure it has power on one of the fuse blades after you take the fuse out. This fuse is fed by two more fusible links that are over by the starter relay.

The more I think about it, you said it started charging, so it must be intermittent. I would be more suspect of the lightgreen/red wire touching metal somewhere, or something wrong with the alternator. See if this place you are buying the alternator from will test the new one for you.

 

ok this is getting wierd?? I cut the green/red wire off at the alternator with truck running, the light stayed on. Then I started puting a connector on the wire, to put the wire back together, I unpluged the clip from the alternator to put black electrical tap around the wire,Then i pluged the clip back into the alternator,(with truck running)and it started charging??????????? but I don't know how long it will charge for?? and I was playing with the clip a few days ago just to make sure it was making a good conection and it was, so I don't think it would be the clip???

 

Just took the truck for a test drive, 5min down the road the light came back on??? what the !@#$

 

I will ask again.

I do not know what system you have, if its the 200 AMP system it sounds like you might have a bad ground on the ground wire (black wire) running from the Alternator to ground.

I do not know the "CLIP" that talked about as I do not have a truck like yours but I would not cut or hook anything up with the engine running.

I am well versed in electronics and have the two basic prints of the FORD Diesel charging systems but my wire colors may differ from yours.

I do not show a "orang/blue" wire at the alt, or a "white/yellow" on my prints, I do show a "Light Green/Red" wire on both prints coming from the Charge Indicator.

There are only three wires leaving the Alternator on one system and four on the 200 Amp system.

You said that you had a voltage at one point so you have a voltmeter and we can use it to measure voltage drop.

I do not have a FAX number.

 

yes i know i shoudn't be cutting wires but i am getting desprate to find the problem!
yes i have a friend with a multimetre that is helping me but he won't be home till tomorrow. I have 2 wires coming out of the alternator clip orange/blue & green/red and the biger wire black/orange coming out of the back of the alternator so three wires at the alternator

 

Well from what I can tell you do not have the 200 Amp Alternator so here is how yours is suppose to work:

Generator Circuit

Circuit Description

Your Black/Orange Wire Big
Battery Positive Voltage (B+) Output
The generator output is supplied through the Battery Positive Voltage (B+) output connection to the battery and electrical system.

Your Green/Red Wire
I Circuit
The I circuit, or ignition circuit, is used to turn on the voltage regulator. This circuit is powered up with the ignition switch (11572) in the RUN position. This circuit is also used to turn the charge indicator lamp on if there is a fault in the charging system operation or associated wiring circuits.

Your Orange/Blue Wire
A Circuit
The A circuit, or battery sense circuit, is used to sense the battery voltage. This voltage is used by the voltage regulator to determine the generator output. This circuit is also used to supply power to the generator field coil. This circuit is hot at all times. This is also connected back to the load distribution point and is a protected circuit.

Inside the Clip OR Jumper Wire
S Circuit
The S circuit, or stator circuit, is used to feed back a voltage signal from the generator (GEN) (10346) to the voltage regulator. This voltage, typically half battery voltage, is used by the voltage regulator to turn off the charge indicator lamp.

I will get back with you soon.

 

INDICATOR LAMP STAYS ON, ENGINE RUNNING



C1: CHECK FOR OPEN A CIRCUIT
C2: CHECK FOR SHORTED I CIRCUIT
C3: CHECK S CIRCUIT FUNCTION
C4: CHECK FOR OPEN S CIRCUIT
C5: CHECK STATOR OUTPUT VOLTAGE
C6: CHECK GENERATOR OUTPUT VOLTAGE

C1 CHECK FOR OPEN A CIRCUIT
Measure voltage at test point A on the voltage regulator.
Is voltage at test point A equal to battery voltage?
Yes
GO to C2.
No
CHECK fuse or Fuse Link in Circuit Orange/Blue and REPLACE if required. If OK, SERVICE open in Circuit Orange/Blue.

C2 CHECK FOR SHORTED I CIRCUIT
Remove three-pin generator regulator connector.
Turn ignition switch to RUN position.
Is indicator lamp on?
Yes
SERVICE short to ground in Circuit Green/Red.
No
GO to C3.

C3 CHECK S CIRCUIT FUNCTION
Install generator regulator connector.
Remove one-pin S connector.
Connect wiring harness S terminal, Circuit 4 (W/BK) to the positive (+) battery post using a jumper wire.
Is indicator lamp on?
Yes
REMOVE jumper wire. GO to C4.
No
REMOVE jumper wire. GO to C5.

C4 CHECK FOR OPEN S CIRCUIT
Remove three-pin generator regulator connector.
Measure wiring resistance between the one-pin S connector and the S (center) pin of the generator regulator connector.
Is resistance greater than 1 ohm?
Yes
SERVICE open or excess resistance in Circuit 4 (W/BK).
No
CHECK for loose or bent pin in voltage regulator or connector. If OK, REPLACE voltage regulator.

C5 CHECK STATOR OUTPUT VOLTAGE
Start engine.
Measure voltage at the S terminal on the back of the generator.
Is voltage at least 1/2 of battery voltage?
Yes
GO to C6.
No
FIND the cause of low generator output.

C6 CHECK GENERATOR OUTPUT VOLTAGE
Measure voltage at the B+ terminal on the back of the generator with the engine running at 2000 rpm and all accessories turned OFF.
Is voltage greater than 15.5 V?
Yes
FIND the cause of high output voltage.
No
REPLACE voltage regulator.

Let me know what you find.

 

ok thanks ,I won't be able to do any testing till tomorrow, but it sounds like your doing some homework I really appreciate the help!!!! I can't give up. $80-$90 dollars an hour i just can't justify taking this to ford!!

 

It figures, i want to do some testing today and the stupid battery light won't come back on?

 

This doesn't make sence? on (c2 check for shorted I circuit) I remove the three pin connector and turn the ignition switch to run position. This is saying the light should go out but if it stays on there is a short to ground in circuit green/red ,I think the light should stay on if the truck is not running because the alternator is not charging??
Am I Correct???