Battery Light Troubleshooting Help! ('97 2.3L)

[RonD]

+1 to what ericbphoto said

But just to clear up the names of things
The rotor is the part that spins and it has coils, also called field coils because they generate a magnetic field, the rotor's fields is what needs to be "excited", which is done by the green wires voltage, key on

The Other Fields are the stator, these are in the case of the alternator, there are 3 field coils and they generate AC voltage as the rotor spins, each of these fields has a set of diodes that convert the AC volts to DC volts.

I generally call the rotor the rotor, and ignore the fact that it has field coils, lol, just less complicated IMO
And I call the stator "3 Field coils" because that also what they are.

The Rotor is what needs to be excited so the 3 field coils(stator) can generate AC volts, this "excitement" comes from green wire first then alternator takes over
Rotor usually gets 7-9 volts "excitement", to produce it's 13-15volts as needed

 

[tomw]

How can I add to the above two posts to indicate that the 'field' current is limited or adjusted to vary the output voltage of the alternator. The regulator provides the 'field' current at startup, and must somehow diddle with that to adjust for battery & load as necessary to keep the voltage within tolerance and to not 'cook' the battery.
Can we now get a bit on the 'smart' regulators and what they are really about? How does it know that you are only going to the corner for a loaf of bread, and re-charge the battery after short trips... and yet not overcharge on the trip to Yellowstone? Hmm.
tom

 

[RonD]

How can I add to the above two posts to indicate that the 'field' current is limited or adjusted to vary the output voltage of the alternator. The regulator provides the 'field' current at startup, and must somehow diddle with that to adjust for battery & load as necessary to keep the voltage within tolerance and to not 'cook' the battery.
Can we now get a bit on the 'smart' regulators and what they are really about? How does it know that you are only going to the corner for a loaf of bread, and re-charge the battery after short trips... and yet not overcharge on the trip to Yellowstone? Hmm.
tom

Electromotive force is how voltage regulator "knows" how many amps to output to maintain correct voltage range

The battery and vehicle are on one side of this, the alternator and voltage regulator are on the other side.

The alternator generates the electromotive force, the regulator "monitors" this force.

Basically regulator monitors "push back" against this electromotive force

After you drain the battery by using starter motor, the alternator starts up and there is very little "push back" in the system so regulator outputs high voltage, 14.5+, to the battery and vehicle systems.

As the battery recharges it starts to push back voltage as it gets fully recharged, regulator reduces voltage as push back increases until it settles in at 13.5-13.8v.
When you turn on the head lights and/or heater fan to high, push back drops again, regulator increases alternator output as it drops to maintain the 13.5-13.8v.

This works OK but is not optimal, its a very basic system, using a microprocessor to monitor voltage and control alternator output would help extend battery life and provide a more stable voltage through out the vehicles electrical system.
But it comes at a cost, lol, adds an extra failure point to the charging system.

Like anything new, it has had its "growing pains", like transition from carbs to fuel injection, the "computer controlled" charging systems need extra level of understanding to diagnose issues.

And when there is a problem we all wish for the "good ol' days" and hate the new stuff
Just like carb and fuel injection

 

[BeeCee]

Alrite, so it looks as though it's indeed the alternator.


After multiple drives, testing for voltage @ battery is still coming in @ 14+v's after running for a while, and not dropping down to 13.5-13.8v.


It also appears to be having its affect on the battery now as well, because now my battery gauge is slowly declining, whereas before when this issue first arose the battery gauge was completely fine. After starting up truck this morning I noticed battery gauge was alot lower then it has been prior.

 

[kimcrwbr1]

Normally the idiot light is controlled by a diode. Maybe put a new regulator in the alternator and troubleshoot from there?

 

[RonD]

Normally the idiot light is controlled by a diode. Maybe put a new regulator in the alternator and troubleshoot from there?

Yes, +1 to that

Whether to replace just the Voltage Regulator or the whole alternator is always a choice.
In this case I would bet money that the Voltage regulator is the only problem(yes failed diode) and just replacing that part would fix the problem.

The choice is that you have to pull out the alternator to change regulator, and if the alternator has been in the vehicle for over 200k miles it may be close to having failed field or bearings, so that's the choice
If its easy to get alternator out and back in then just do the regulator, if its a pain to get in and out then swap out whole alternator

 

[BeeCee]

I ended up just purchasing the whole alternator. Not sure if it's the original, I'll prob know when I pull it off and look at sticker/labeling, but it looks older...and it has to come off regardless, so I figured I would just replace the entire alternator. Also purchased a new belt while I was at it.

Going to install tomorrow morning, hopefully this cures the light/gauge woes!

I'll keep everyone posted!

 

[kimcrwbr1]

Disconnect the battery and fully charge it with a slow charge. Measure the voltage and let sit overnight if the voltage drops the next day just replace it as well.

 

[BeeCee]

Alrite guys, just wanted to keep everyone posted with an update.


So the other morning, I attempted the replacement, as planned.

Although what really could have been an easy hour job, turned into a nightmare.

The alternator was indeed replaced prior, and everything was stripped from the prior replacement. Got the first bolt after a half hour of slowly backing it out, just to find everything is all stripped. And of course, the second and third bolts snapped halfway out.

So now I'm in the hunt for a damn alternator bracket. Which of course is now discontinued by Ford.

Haven't found shit online after some heavy searching, and been striking out with junkyards. Hoping to possibly find one tomorrow at this u-pull-it.


If anybody has a spare one, please let me buy it off of you lol.

 

[Denisefwd93]

Alrite guys, just wanted to keep everyone posted with an update.


So the other morning, I attempted the replacement, as planned.

Although what really could have been an easy hour job, turned into a nightmare.

The alternator was indeed replaced prior, and everything was stripped from the prior replacement. Got the first bolt after a half hour of slowly backing it out, just to find everything is all stripped. And of course, the second and third bolts snapped halfway out.

So now I'm in the hunt for a damn alternator bracket. Which of course is now discontinued by Ford.

Haven't found shit online after some heavy searching, and been striking out with junkyards. Hoping to possibly find one tomorrow at this u-pull-it.


If anybody has a spare one, please let me buy it off of you lol.

Are the bolts broken off in the engine? or inside the bracket? if they are you could take it to a machine shop and probably have it taken care of faster than you locating one

 

[BeeCee]

They are broken off in the bracket.

The bracket is still on truck, not off yet. I thought just replacing the bracket would be easier, but sourcing one turns out to be way harder than expected. I guess that might have to be a last resort.

 

[ericbphoto]

Yes. That could be fixed. But a junk yard bracket is definitely the easier way if you can find one. Maybe someone reading this thread can shed light on whether the brackets from any other engines will interchange. You probably have a very wide range of year models that will work.

This message composed solely of recycled electrons. Go green!

 

[BeeCee]

Yes. That could be fixed. But a junk yard bracket is definitely the easier way if you can find one. Maybe someone reading this thread can shed light on whether the brackets from any other engines will interchange. You probably have a very wide range of year models that will work.

That's a good idea, that would be great.

It's a '97 2.3L 4cyl manual.


I don't know if anyone has any information on this as well, but it seems as though the 93-94 bracket might be different from 95-97 possibly.

The part #'s are different, the 93-94 # is F2TZ10A313B & the 95-97 is F57Z10A313A.

 

[Denisefwd93]

eBay how I got my driveshaft by the time I drove around called places asking & being ignored and treated like I didn't know what I was talking about. Found one on eBay, it ordered it and had it in 2 days I'm sure you can find your bracket on eBay all the major salvage yards seem to be on there

 

[BeeCee]

Trust me, been all over eBay. I wish someone on ebay had it.

Not one on there. Bunch of 3.0's & 4.0's, no 2.3's though.