Alternator charging problem?

Hi and thanks for using 2CarPros.com.

It sounds like the alternator is bad and cannot keep up with the demand. Here is a simple test to check if it is working:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Try that test and let me know what you find. Additionally, if you are not comfortable doing it yourself, most parts stores can check it on the vehicle and will do it for free.


Let me know what you find or if you have other questions.
Take care,
Joe

The battery and alternator was tested at a parts store. Both were fine, even put a brand new alternator on for good measure and it was still the exact same.

Is the serpentine belt self adjuster keeping everything tight?

Yes, idle voltage is fine at idle and above idle.

If it is below 45° it takes about ten minutes to start charging in the morning as well.

Hi again. If the alternator and battery are good, I would start checking grounds. A weak ground could be an issue. Also, confirm that the fusible link is in good condition and making good connection. I have attached a wiring schematic for your vehicle. Take a look at it and let me know if this helps.

Note: I had to get two pictures for the entire schematic. Sorry about that.

Let me know.

My truck is not charging and I have changed alternator and nothing. I have three wires going into one fusible link. Could this be the starter?

hi if it is not chargeing it has to be in the charge system.check plug at alt check all fuse links check voltage regulator. check all fuses good luck feel free to write again billymac

I did an automatic to manual transmission swap. new starter hooked everything up like it came out. cranked the truck while it was idling the interior light went out. checked alternator it was bad. put new one on still no charge. I have looked at everything still nothing.

Most commonly you will find the brushes are worn. Those come as part of a new voltage regulator. The regulator can be replaced separately by removing the four bolts in the four corners of the regulator. The new one will come with a toothpick in the hole just to the right of my blue arrow. Leave that in place while you bolt the new regulator to the generator. Once finished, the last step is to slide out that toothpick. You'll hear two faint clicks as the new brushes snap into place.

Alternator works OK and Battery is OK , but the system will not charge . Is there a fuss link in the charging system. I have a green and red strip wire from the Alternator that is not hook up could that be the problem ?

I have had the Alternator check at 2 places and they read the same. The Battery in new. I have check all the wiring from the Alternator and found a green with a red strip on it but can not find where it hooks up. also does the charging system have a fuss link in it.

Yes the wiring needs to be tested the green and red wire goes over to the voltage regulator. Here is a couple guides that will help you get the problem fixed. The voltage regulators are separate on this truck on some models.

https://www.2carpros.com/articles/how-to-check-wiring

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here is a wiring diagram (below)

Please let us know what happens.

Cheers

OK his some more on the charging system problem. I took my meter and check all the wiring, the fuses have been removed before I bought the truck. I have load tested the charging system and still now power coming through. I took the leads of the Alternator that go to the starter rely, they should be hot all the time. I removed them and check for power no power while it was running from the alternator. I pulled the alternator and check all the wiring they have a clear path. but I check the rest of the Alternator nothing

I posted the wire diagram for the alternator there are 3 power inputs coming into the alternator from a fuseable link.See if you have those three power inputs into the alternator.

I have the same diagram as the one you have sent me. The fuss able links where all removed some time ago and the wires where routed back to the same points less the fusses. The system has worked ever scent I have owned the truck, until lately it will not charge the battery up. I cut the power lines from the Alternator and fired the truck up and check the out put no out put from any point of the Alternator. So I am figuring the Alternator is got to be the trouble. I am going to have it bench check one more time or just get a new Alternator . This getting nuts. Its a simple system almost like a two wire Alternator. Oh well.

With everything hooked up was there power going to those three wires at the alternator?If not you have to start by getting power there and adding a fuseable link also.

The two lines you see on the schismatic that come off the alternator they go to the starter rely from there one goes to the battery and one to the starter. So between the alternator and rely they our hot all the time so long ass they our still connected to the battery . But when you start the engine and load the electrical system the alternator does not go up in charge. If you remove those cables so they our not pulling from the battery there is no power on the lines, being this is the lines that charge the battery there should be power there while the alternator is running but there is no power. You pull the alternator off the truck to bench test it you get 13.8 volts on the bench test. All test our done with a full charged battery. So I am assuming there has to be a short in the alternator I will have it check one more time.I think it will have to be the alternator every thing else checks out OK . But why on a bench it shows OK ??? But when you connect it to the truck nothing ??

Without power going into the alternator it wont charge also with the key in the run position and engine off do those three wires off the fuseable link in the wire diagram i posted have battery voltage going into the alternator?Sounds like you have no power to one or all those wires.

Yes the three wires have power. But still no generation from the alternator . Its just about like a two wire alternator it so simple thats why I figuring some tester have to be wrong .

Are the two white wires with the black strip connected together?

OK this has been one crazy ride. I figured the problem out and even the ford tec at the plant could not understand what would cause the problem. If you look at the diagram you will see dash indicator light look real close and you will see it is fussed if this fuss blows it cuts out the charging system all together. I understand that most new cars our running this same system , if you have a dash light indicator and it goes out it will not send the signal to the alternator to charge and the simple way to check it is turn on your ignition switch and if the light does not come on and the alternator does not want to charge check it it could the problem. I remember working on a Mercedes Benz truck with the same problem and the repair manuals do not say a word about it after 2 alternators and hours of hair pulling we found the problem the light in the dash indicate r was out. So remember that a lot of new cars our coming out with this set up. Thanks for your help.