I have a 1994 V6 (automatic) Ranger.
For some reason the battery isn't charging.
I can charge the battery with a charger in the garage and it tests 12.4v or so connected up in the truck when it's not running.
When I check the battery with the truck running I still only get 12.4v or so.
I replaced the alternator and no change.
Fuses visually look ok, and I replaced some of the smaller ones, this was a city truck and it had roof lights previously removed before I got it and they had fuses in different spots than spec.
The dash gauges (speedo, fuel, battery etc) and dash lights don't work either, all other lights and electrics work fine.
I can drive the truck until the battery dies, charge the battery in the garage and drive it more until battery dies again. So I think it's unlikely that it's the battery.
Only other issue is trans slips some until it warms up.

Is there a wired fuse in this model year?
Could it be fuse box itself? How the heck can I test that?

 

The Battery Light on the dash is the ON/OFF switch for the alternator

Battery light should come on with key on, does it?
If not then alternator will be turned OFF full time


Easy test for charging system for any vehicle
Key OFF
Use alternator's metal case for volt meter ground
Test for Battery Voltage on B+, thats the stud/nut connection on the back of the alternator, should read exactly the same volts as battery, if not then in 1994 the Fusible Link is blown
Fusible link is connected to Starter Relay(solenoid) on inner fender, it on the same post as the battery positive cable

Unplug the 3 wire connector from alternator(this is the voltage regulator plugin)
Test the Yellow wire, should have battery voltage, if not then in a 1994 a 15amp fuse in the engine fuse box is blown, fuse 20 maybe

Test Light green wire, should be 0volts
Turn key ON
Retest light green wire, should now show Battery Volts, this is the ON/OFF voltage from Battery Light on the dash
This voltage comes from a fuse in the cab, maybe fuse 18, its not listed, but should be 10 or 15amp fuse


An alternator can NOT generate voltage just by spinning it, it must have "startup voltage", and that's what the battery light circuit is for, the light green wire has the startup voltage needed to "startup" alternator generating its own voltage, when it does "startup" then battery light goes OFF because its voltage is no longer needed

Also make sure the white wire "jumper" is in good condition and plugged into the alternator's single plugin

In 1994 Fuse 7 in the cab fuse box powers the gauges, 15amp, but not the Battery Light



A Fusible link is a wire about 6"-8" long, it is made of a softer metal wire and special insulation that won't burn, both the wire and insulation vaporizes when it "blows" so it can't start a fire
These are often used as "slow blow" fuses for alternators where AMPS can vary widely and some times spike, a regular fuse would blow in these applications
A Fusible link can blow, the point of using it, lol, and can be replaced
If B+ terminal on alternator has 0 volts then fusible link is blown
In 1994 it is a 12gauge fusible link, most likely a Grey wire connected to starter relay post
You may have to untape or cut back the harness at starter relay end to locate where it has separated, and to replace it

The alternators B+ wire will be 10gauge, larger wire than 12gauge fusible link, it runs into the harness to the starter relay area when its connected to the fusible link, and then to the starter relay post with battery positive cable
A fusible link is always 1 or 2 sizes smaller than the wire/circuit it is protecting

 

I got battery voltage on all of those points.
Started the truck and voltage went down to 11.97 at battery terminals and at the B+ on the alternator, left it running a bit, retested and it’s at 11.94.
So I think that narrows it down the the battery or the alternator as the problem?

 

Alternator is the problem if wires tested OK

 

Okay I have a 94 2.3l I followed the steps as started above. I used a multimeter to check the fusible link and that was fine then I checked the connector on the alternator (yellow wire) and that showed zero volts so I traced it back to the fuse box in the engine bay and the fuse was missing but not only that a lot of the fuses were loose so I took apart the fuse box and there's no connections behind it so my question is what does that yellow wire connect to after the fuse box?

Upon further examination, I traced the yellow wire from the alternator back to the fuse box, which was in a different location, then I traced wire from the other side of the fuse all the way down to a clip that has 2 weird coming out of it, (light green wire with a yellow stripe and a black wire) the clip ends there I do not know where the mail connection to this female plug goes
Please help

 

Answered here: https://www.ranger-forums.com/genera...attery-169336/