1999 f250 will not charge battery

Battery problem or alternator or battery cable's ,connections etc.... Do you know how to test automotive electrical circuit's ? Voltage drop testing ? Using a voltmeter to test the battery voltage level ,12.6 is fully charged , 14. 00 with engine running .
Voltage Drop Testing the Starter
Charging System Problem Voltage Drops

I would say that you have a bad battery . If the alternator is charging ok but the battery is bad all the current will go to the dying cell . Have a load test done on the battery to eliminate it as a source of a problem. Next have the alternator bench tested as there may be a problem in the rectifier pack

Is the battery charged up? It should be at least 12.6 volts.
If you have a voltmeter, do a voltage drop test on the battery cables, posts, terminals-looking for high resistance in passing current to the starter. Bad cables or terminals if you have high resistance. Youtube has videos of voltage drop testing.
If you don't have a voltmeter, take the starter off and have a parts store test it for free. If starter and battery are good, check for power on the small purple wire at the starter solenoid with key held in crank. If power there, and starter and solenoid were tested, then could be the battery ground, or a bad battery cable, a loose connection on the starter, or starter not bolted down tight. Maybe the starter and solenoid tested okay, but still not good. That's rare but not unknown.
If no power on the small purple wire in start, check the starter relay-is that what clicks? Try a new relay.
Good luck, half the time it's the starter, the other half is one of the above. If the click is at the starter, you can assume that the start circuit is good-look to the battery, cables, starter, or a loose, poor ground or cable connection.

sounds alot like a bad battery

your battery is probably junk. remove it and take it to your auto parts store and have it tested.

Hi,
The Alternator is JUNK, sorry.
Regards,DT

Sounds like a weak battery.
Take it out and charge it up.
Then put voltmeter across battery when trying to start.
Before starting it should read 12.5.
When starting should drop to 10.
If below 9 then either bad battery or excess starter draw.
If you stop cranking it should come back up to 12 at least.
If not, battery is not holding charge.
When it does start, must go over 12.5, and when reved, must go to at least 13.5.
If not, then alternator bad, or dirty battery terminals, engine ground, loose belt, etc.

Do you have corrosion around the battery terminals, Check the terminals take them off check inside and check the battery ground to chassis. Take it off sand the body with some sand paper and put it back on. Sounds like a problem with the battery itself.

Also have you check your alt output.

You can try this to verify that the starter is good or bad.


Starter Testing Starting System Voltage Drop Tests NOTE: The battery must be in good condition and fully charged prior to performing this test.
There are three area of the starter motor circuits that voltage drop test can be performed on. These include:

• The starter feed circuit
• The starter ground circuit
• The starter solenoid.

Starter Feed Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of a voltmeter to the positive terminal of the battery.
4. Connect the negative lead of a voltmeter to the starter B+ terminal.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.1 volt drop for each connection displayed on the voltmeter. No voltage should be consumed by the vehicle wiring
     1. If the battery cable connects directly to the starter motor there should be no more than a 0.2 volt drop measured
     2. If the vehicle uses a starter solenoid between the battery and the starter motor terminal there should be no more than 0.4 volt displayed on the voltmeter

Starter Ground Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of the voltmeter to the case of the starter motor.
4. Connect the negative lead of the voltmeter to the negative terminal of the battery.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.1 volt drop for each connection displayed on the voltmeter. No voltage should be consumed by the vehicle wiring
     1. If the battery cable connects directly to the starter motor there should be no more than a 0.2 volt drop measured.

Starter Solenoid

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of the voltmeter to the case starter B+ terminal.
4. Connect the negative lead of the voltmeter to the lug (the starter M terminal) that connects the starter solenoid to the starter motor.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.2 volt drop across the starter solenoid displayed on the voltmeter.

In general, there should be no more than a 1.0 volt drop throughout the entire starter motor feed and ground circuit. Any voltage drops measured in either the feed or ground circuits after connections have been cleaned will require replacement of the affected battery cable. Typically, any voltage drops measured in the solenoid are repaired by replacing the starter motor.

I looked at all the steps for replacing the blower motor...they should not have messed with anything that would have affected the operation of the starter.