i replaced the alternator and its still not charging

[RonD]

2002 Ranger, fuse 41 passes 12volts to the EVAP purge canister and transmission solenoids

The power for fuse 41 comes from EEC relay(PCM Relay) which is powered by a 30amp fuse(#7)

Battery"+"-------Fuse7(30amp)---------PCM Relay---------fuse41(20amp)-----------EVAP/Trans

Fuse 7 has power all the time
PCM relay closes when key is turned on, so fuse 41 has no power when key is off only when key is on.

This is a temporary fix to get you moving not meant to be used in place of Battery Light circuit.
You need to find out what happened to the green wire, and maybe run a new "green" wire back to the dash.
And check it at the 3 wire connector, the pin in the connector or the wire could be the problem.
After cutting the green wire check it's voltage again, could be you just need to replace the connector

When green wire is powered and engine running you should have above 14volts at the battery, but under 15v, after a few minutes that voltage should drop down to about 13.5volts.
Alternator's voltage regulator will generate above 14volts if battery is drained, like from using the starter motor.
But constant voltage above 14volts will damage the battery long term.
So voltage regulator will drop the voltage below 14volts after the "recharge"

 

[it-broke-again]

I tried bypassing the green wire but got nothing still

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[RonD]

The charging system is not that complicated, you are missing something

B+ wire on the back of alternator is used to charge the battery, output wire, so it is hooked directly to the battery, which is why it has 12volts all the time, there are fuses or fusible links of course, and on the yellow wire

Yellow wire is to monitor voltage on the system, sensing wire, so it is hooked to battery all the time.

The above 2 wires should always show battery voltage, key on or off doesn't matter, if one or both show no voltage then a fuse or fusible link has blown(or battery is unhooked)

White wire, short loop, connects the voltage regulator to the Stator(wire coils in the case of the alternator)
On newer alternators this connection is internal, so no white wire is seen.

Green wire is to power the alternator(voltage regulator) before it starts making it's own power, Battery light is also on this wire.


How it works:
Voltage regulator send 6volts to the Rotor(3 fields), this makes the 3 fields electro-magnets.
The green wire supplies this voltage, 12volts, so alternator can 'start' to generate it's own power, if there is no power to "get the ball rolling" then alternator is just spinning, no power is generated, because there are no magnetic fields.

The engine spins the rotor, the spinning magnetic fields generate AC voltage in the 3 Stator windings in the alternators case.
Diodes are used to change the AC into DC Volts
The DC volts are sent out on B+ terminal.

The voltage regulator adjusts the Rotors 6volts up or down to increase or decrease the voltage on B+, as low as 5volts and up to 9volts.
This is how voltage regulator adjusts output voltage from 13.5v up to 14.9volts, or increases voltage as more power(amps) are needed


1 wire alternators use an RPM switch, when RPMs reach a certain level the 12volts on the 1 wire(B+) is used to "get the ball rolling" and once voltage is being generated B+ then outputs the 13.5v to 14.9v

 

[it-broke-again]

I'm going to replace the connector and check all of the wires again tomorrow

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[it-broke-again]

I finally got a break in the weather long enough to Mess with it and after I replaced the connector I ended up having to jump the yellow wire to the voltage regulator to get it to charge. have yet to look into the yellow wire but I have it running off of a inline fuse holder and some wire leading to the battery

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[RonD]

I thought you tested that wire before and got 12volts??

There is a blown Fusible link if yellow wire has no voltage

 

[RonD]

I thought you tested that wire before and got 12volts??

There is a blown Fusible link if yellow wire has no voltage

 

[it-broke-again]

I tested it and it seems to be getting like 11v

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[RonD]

If battery voltage is 11v then that would be correct, if battery voltage is 12.5v then there would be a problem.

Voltage tests are all based on battery voltage at the battery, key off, and then key on, thats what you are comparing it to.

 

[it-broke-again]

Then why won't it work when I hook it back to the harness but it does when it's hooked to the direct hot I made

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[RonD]

You are there, not me, so can't say.

But it isn't a complex system
Test battery voltage, lets say it is 12.5volts
test B+ wire, it will be 12.5v
test yellow wire, it will be 12.5v

 

[zekew64]

I finally got a break in the weather long enough to Mess with it and after I replaced the connector I ended up having to jump the yellow wire to the voltage regulator to get it to charge. have yet to look into the yellow wire but I have it running off of a inline fuse holder and some wire leading to the battery

I have looked at a wiring schematic and have a solution.

First, is the wire you jumpered yellow with a white stripe? If so, that wire is the "A" circuit wire and goes to the regulator for fuse #7 (30 amp). Let me guess: You did not check continuity between the fuse and the connector, did you? The reason why, I'm willing to bet that your jumper wire worked is because the yellow wire is bad internally. Do a continuity check, and if you get an "infinite" reading, it indicates that the wire is corroded or broken.

By the way, in all of the wires on your charging circuit, there are NO fusible links, as the alternator is protected by the 30 amp fuse in the battery junction box among other fuses. Also, the other yellow wire is the ignition wire that goes to your ignition switch. Check the continuity on that wire (or turn the key on, and see if your other prestart lights come on and go out); if that wire has no continuity, then the ignition switch itself is not getting power, and needs replacing or repaired.