Hello, I have a 98 ranger 5 speed; and I’ve been having problems with my battery charging. Now I’ve had the alternator checked I recently put a new battery in it and I’ve checked all my ground wires around the truck. The main problem I’m having is when I turn my headlights on the battery starts to drain immediately. I’ve ran all of the wires that I know to check down and have found no bald spots or shorts. I’m open to any suggestions or help that anyone here would be able to offer me. Please and thank you in advance!!!!

 

Welcome to the forum

You need to get a Volt Meter

Key off, set Volt Meter to DC Volts
Test battery voltage
Should be 12.8v if battery is new
12.2v is a dead battery

Once you have Battery Voltage remember it

On the alternator is a 2 or 3 wire plug in, unplug it

On back of alternator is a Stud/nut terminal, called B+ terminal, hold volt meters black probe on alternators metal case(ground) and touch Red probe to Stud/nut terminal, should see Battery Voltage(exactly), this is a direct connection to the battery thru a large fuse
If no or low voltage you have a blown MEGA fuse, or corroded connection

On the 2-3 wire plug there will be a Yellow/white stripe wire, using alternator case still as the ground, touch red probe to that wire, should see Battery Voltage
If not then ALT SYS FUSE is blown, 30amp fuse in engine fuse box

On the same connector will be a Light Green/red stripe wire, test its voltage, should be 0, no volts
Turn on the key
Test Green wire voltage again, should be Battery Voltage now
If not Fuse #15 in cab fuse box is blown, 7.5amp fuse
This is the BATTERY LIGHT fuse and wire, if your Battery Light does NOT come on when you turn on the key then this fuse is blown and alternator can not work

If all wires test OK then alternator is bad, new or not, tested or not, simple as that

You only need to test these 3 wires on any charging system to see if vehicles system is OK

Plug alternator's connector back in
Start engine

Test battery voltage again, should now read above 14volts, 14.5-14.8v just after start up
This means alternator is working, the alternator powers ALL the vehicle electrics, battery is ONLY USED to start the engine

After engine runs for 5-10 minutes or so, do not shut it off and test battery again, should now be under 14volts, 13.5-13.8v, this is the way it should stay until engine is shut off again
Turn on head lights, heater fan to high, any and all electrics, test battery voltage again, should still be at 13.5-13.8v

 

 

Good work

Thank for posting the update, and the FIX

 

"On the same connector will be a Light Green/red stripe wire, test its voltage, should be 0, no volts
Turn on the key
Test Green wire voltage again, should be Battery Voltage now
If not Fuse #15 in cab fuse box is blown, 7.5amp fuse
This is the BATTERY LIGHT fuse and wire, if your Battery Light does NOT come on when you turn on the key then this fuse is blown and alternator can not work"

This is where I'm stuck. I do this test, and it fails. That is, I hook up my circuit tester to ground and to the green/red wire (with the key on), and get nothing.

I am also not getting a BATTERY LIGHT in the instrument cluster with the key on.

So this seems like it. But ... there is no Fuse #15 in my cab fuse box. I've tested some of the more likely fuses, but they all are good (e.g., the GEM fuse, the Instrument cluster fuse--didn't bother with 7.5 amp fuses for stop/turn with trailer).

I've got an alldatadiy manual. I'm not sure what the verbiage is for the correct fuse, so don't really know where to look.

Any ideas?

I have a 2001 Ranger, 4.0L SOHC, 4WD.

 

In 2001 check fuse 11 in cab fuse box, 7.5amp thats for the Charge light, same as battery light

Yes thats your problem, green wire provides startup power for alternator to start making voltage

 

Thanks, RonD.

Unfortunately, Fuse 11 is good. That is, with the key on, and testing both sides of the fuse with a circuit test, both are hot. (I've also taken it out for a visual inspection, and it looks good.)

In addition, the instrument cluster lights up, but that wouldn't happen if F11 were blown. (Was I mistaken in thinking that there'd be a battery light that would come on with the key in the on position and the engine not running?) It does have an alternator gauge and when the key is on, the needle moves up a little. But when I'd start it, nothing else would happen with the needle.

When I finished checking Fuse 11, I double checked the green wire (still no juice to it when well grounded on the other end of the tester to the chassis). Then I put it all back together and started it one last time. This time, for about two seconds, the needle on the alternator gauge moved to the normal (charging) position, before going back to the non charging position.

So there's something intermittent going on.

I have no idea what.

 

Yes on 2001 there is a Battery icon light, should come on with key engine off, then go off when engine starts IF alternator is working

According to 2001 manual Battery Light should be next to the 1 on the tachometer, just above airbag light

If fuse 11 is OK then problem is in the cluster or the green wire

The Battery light gets 12v from fuse 11 but needs to be Grounded by the alternator's voltage regulator so the light bulb can come on

So if there is a problem with green wire or cluster then no battery light

You will probably need to pull the cluster out at this point, and check the 10 pin connector on the back, it has both the 12v wire(yellow, pin2) and the light green wire(pin 3), so you can test both and the circuit in the cluster

If you need the truck now you can give the green wire 12v and start the engine, but you need to disconnect it when key is off or alternator will drain the battery within a few hours, it will actually try to turn the engine over via fan belt, lol

2001 cluster wiring diagram here
Connector is bottom one, 10 pin, C220C, pins 2 and 3

Also charging diagram but not much to it, same as all charging systems, they are very simple wiring wise
The battery light bulb also has a bypass resistor(470 ohms), they all have this, this is in case the bulb should burn out, so alternator would still get startup voltage thru the resistor, a light bulb is less resistance so power travels thru it when its working

 

RonD,

Thanks for the help. Here's where I am.

1. Pulled the cluster.
2. On the C220C male side, the yellow wire is hot with the key on.
3. On the C220C male side, the light green wire is never hot (key on or off).
4. From the female side of the connection on the cluster, there is 0.380 ohms resistence (when the multimeter is set to 2k setting) between pin 3 and one side of the resistor and one side of the bulb.
5. From the female side of the connection on the clustor, there is 0.405 ohms resistence (when the multimeter is set to 2k setting) between pin 4 and the other side of the resistor and the bulb.
6. I'm getting continuity between pins 2,3,4 and the bulb and resistor.
7. The resistor tests good, and the two sides of the bulb test good (both with 0.380 ohms when the multimeter is set to 2k setting).
8. I've swapped the battery bulb with another working bulbs, so that is not the issue.

I'm not sure what this all means. Or what to further test to narrow down the problem.

 

I checked at the alternator connector again after hooking the instrument cluster back in.

I got 12v at the yellow wire and at first 3.7v at the green wire, but then 0v. Since I didn't have a helper, I couldn't see if the battery light came on at the instrument cluster.

So it's something intermittent.

 

With key on you should have 12volts on light green wire, same volts as on the yellow wire, with connector plugged in

Pins 2 and 3 should show continuity, just a light bulb between them

0.380k ohms = 380 ohms so thats OK and there should be the same between pins 2 and 3, if not then problem is in the cluster, there resistor is between pins 2 and 3, so is the bulb

 

Thanks,

Pins 2 and 3 have 380 ohms without the bulb, 90 ohms with the bulb in. So that all bodes well.

Since the fuse has current flowing through it with the key on, but this circuit is not drawing current, it's some other thing on the same fuse that's drawing the current. Does that seem reasonable?

Next is to test continuity between the green wire at male end of the C220C connection and the alternator connector.

If there's continuity, then along the way there's a short? And if there's not continuity there's a break in the wire?

About five months ago I replaced the complete battery wiring harness. There have been no issues from then till now (that I've noticed). I'm not sure where the green wire comes into that harness to test that connection for a weak point.

 

Problem solved!

When I was changing the wiring harness, I snapped off one of the clips that holds a male-female connection together. When I put it back, I just pushed the parts together as best I could, and it was a pretty snug connection to begin with.

It had worked a little loose. After snugging it back together, everything works, battery light, 12v to the green wire in the alternator connector.

I won't replace the connector with the broken clip, since it's a pain to get to, but will snug everything together either with tape or a zip tie.

Thanks, RonD, for your help with troubleshooting. I learned a great deal from it.

 

Good work

Thanks for the update and the FIX