1994 Ranger 3.0 alternator stumped

[fa1rch1ld]

Got a 1994 Ranger on a trade. Battery will not charge from the alternator. Figured the quick fix would replace the alternator, still not charging. figured maybe the new alternator was bad. So put another one in. Still nothing.

I just tested the yellow/white striped wire with car off. 13v. So this is telling me that the circuit is complete because the battery is reading 13v and so is it at the alternator yellow/white striped is also reading 13v. Wouldn’t this tell me that the wiring has no short or corrosion? When starting the car it goes into the 12v range same at the yellow/white striped. When I plug it in, no jump in volts at the battery. What I’m I missing here?

 

[ShhhhhDougsHere]

I'm just a novice around here so bear with me.

Do you have an individual power wire that goes to the alternator?
How well is your motor grounded?

 

[ShhhhhDougsHere]

I just edited My last post in this thread.

I hope the diagram helps.

Had to edit this post as well.
I left out the word edit.

 

[fa1rch1ld]

I just edited My last post in this thread.

I hope the diagram helps.

Had to edit this post as well.
I left out the word edit.

The ground goes from the battery to frame, correct? I just cleaned that connection up. Still nothing.

 

[ShhhhhDougsHere]

The negative terminal of your negative cable should have a branch on it that goes to the body.
Then the larger wire of the negative cable should go somewhere on your motor.
Believe it or not, I do believe mine goes to the bottom bolt on the starter.
The bottom starter bolt has some stud sticking out and a nut goes on to it.
I believe that's where my negative cable hooks up to my motor.

However my EVTM says it should be bolted to the driver side frame rail.
If I'm reading it right.

Look at G107.
I believe that's the ground wire or negative wire from your battery however you want to say it.

 

[fa1rch1ld]

The negative terminal of your negative cable should have a branch on it that goes to the body.
Then the larger wire of the negative cable should go somewhere on your motor.
Believe it or not, I do believe mine goes to the bottom bolt on the starter.
The bottom starter bolt has some stud sticking out and a nut goes on to it.
I believe that's where my negative cable hooks up to my motor.

However my EVTM says it should be bolted to the driver side frame rail.
If I'm reading it right.View attachment 132638
Look at G107.
I believe that's the ground wire or negative wire from your battery however you want to say it.

Yes, mine is mounted there. It seems pretty secure and tight. To unbolt and clean the contact area would be difficult. Not convinced that it’s the issue. But never know I guess.

 

[2011Supercab]

This post might help

Post in thread 'Replaced VR and then Alternator - still no charge'

Mar 20, 2024

+1 ^^^

Alternator has 3 wires you need to test
B+ is the stud/nut terminal on the back of the alternator
As said above use the alternators metal case as the ground for all tests
Key OFF
B+ should show Battery Volts, leave wire attached, exactly the same as battery volts
If not then a fuse or fusible link is bad
This is the Voltage OUT to Battery positive so has a fuse at battery end of wiring

Unplug the 2 or 3 wire connector on alternator
Test the Yellow/White wire, should also show Battery volts, exactly
If not a fuse in engine bay fuse box is blown
This is the Voltage regulator's...

• RonD

• 

 

[SenorNoob]

The primary ground wire on mine goes to frame, engine block, and one of the starter bolts. All one factory wire.

 

[fa1rch1ld]

This post might help

Post in thread 'Replaced VR and then Alternator - still no charge'

Mar 20, 2024

+1 ^^^

Alternator has 3 wires you need to test
B+ is the stud/nut terminal on the back of the alternator
As said above use the alternators metal case as the ground for all tests
Key OFF
B+ should show Battery Volts, leave wire attached, exactly the same as battery volts
If not then a fuse or fusible link is bad
This is the Voltage OUT to Battery positive so has a fuse at battery end of wiring

Unplug the 2 or 3 wire connector on alternator
Test the Yellow/White wire, should also show Battery volts, exactly
If not a fuse in engine bay fuse box is blown
This is the Voltage regulator's...

• RonD

• 

This post helped. I was able to track down the fault wire

 

[fa1rch1ld]

The primary ground wire on mine goes to frame, engine block, and one of the starter bolts. All one factory wire.

Yes, that’s how mine is setup.

 

[ShhhhhDougsHere]

I'm glad you figured out the problem.

I'm also glad you posted letting everyone know you figured it out.

So what was the problem?

 

[fa1rch1ld]

I'm glad you figured out the problem.

I'm also glad you posted letting everyone know you figured it out.

So what was the problem?

The B+ wire was not reading the same Volts as the battery. That indicated something was wrong with the B+ wiring. Following the line to the Fusable Link, it was toast. Ordered a new 12g fusable link and it fixed the problem—learning pains. Probably didn't need the new alternator.

 

[2011Supercab]

The B+ wire was not reading the same Volts as the battery. That indicated something was wrong with the B+ wiring. Following the line to the Fusable Link, it was toast. Ordered a new 12g fusable link and it fixed the problem—learning pains. Probably didn't need the new alternator.

Thanks for posting the solution.

 

[ShhhhhDougsHere]

Yes thank you @fa1rch1ld for posting what the problem ended up being and the fix as well.

Hopefully now you can take your truck and have some fun with it.