2000 Ford Ranger Charging issue???

[jeremyctry]

So yesterday my truck didn't want to start, I popped the hood jiggled the wires at the battery and started right up. When I went to leave work last night my battery was dead I got a jump disconnected the jumper cables and let the truck run for about 15 minutes before starting my 30 minute drive home. My speedometer was jumping erratically and ABS light flashing on and off. Then when I got on the interstate the truck started surging. I took the next exit praying it wouldn't die at the stop light. But when I accelerated away from the intersection all problems ceased and the truck ran perfectly on back roads at 55 mph for the 32 minute drive home. Now truck wont start again unless jumped. Battery is new Alternator has been tested twice and is fine. When truck is running my voltmeter is only showing 12.87 volts speedometer is jumping erratically again and stereo cuts in and out in and out while driving, at idle everything seems to work fine. What am I missing?

2000 Ford Ranger 4.0 OHV 4x4

 

[Curious Hound]

Sounds like loose connection somewhere - probably close to where you "jiggled the wires". Check all wiring connections for tightness and make sure there is no corrosion. Check positive AND negative (ground) wire connections.

 

[jeremyctry]

that was the first thing I did my neg terminal connection was loose but I fixed that and still no joy.

 

[Curious Hound]

Keep checking. There could be more loose places. especially check the ground wire connection at the engine.

Also, what is battery voltage with engine running? (ie; charging)

 

[jeremyctry]

when running/charging (but not charging) battery is showing 12.87 volts but should be showing 14.5 at least thats what the alternator is putting out.

 

[RonD]

key off, check battery voltage, say it is 12.8v
Leave Volt meter's black probe on battery negative and put red probe on Alternators B+(large wire on back side of alternator).
Should see same volts, 12.8v, if not then Mega Fuse is blown, next to engine fuse box.
Move Black probe to alternators case, should see same 12.8v, if not negative cable has bad connection
Move red probe to battery positive, should see same 12.8v, in not then battery cables are not getting a good connection, check BOTH ends of each cable.

Now put black probe on alternator case and red probe on Yellow/White stripe wire, on alternator's 3 wire connector.
Should see 12.8v, if not 30amp fuse is blown, engine fuse box.

Turn on the key, engine off
Battery Light in dash should be on, if not then 7.5amp fuse in cab fuse box is blown, try fuse #11 or #15, but not sure on 2000

If it all checks out then start engine, Battery Light should go off
Voltage at battery should be 13.8 to 14.9v.
Above 14volts is "recharge" voltage, after 5 minutes or so it should drop to below 14volts or battery will be damaged
15v or higher will also damage battery

 

[jeremyctry]

So yesterday morning I started at my battery cables and found the loose neg terminal connection, fixed that and realized my battery was dead. So I hooked up the charger and let it charge for a bit. after an hour it still didn't have enough juice to start so I jumped it and it fired up I drove it around the block abs light flashing on and off and speedo jumping erratically, I realized I still have a problem. So I checked for resistance on all but the 2 white and black striped and the 1 green and red striped wire. I found 0.01 resistance on the black and orange striped wire. I jerked my alternator and had it tested at Oreillys and Autozone both told me it was good Autozone told me it was putting out 14.5. So I started chasing my orange and black wire looking for a problem. I got all the way to the mega fuse (125 amp) and checked it for resistance 0.00 confused now I started to put it all back together. After getting all the wires hooked back up correctly I checked for resistance again now I got 0.00 resistance even on the orange and black. At this point I had to stop and get ready for work because my ride was on the way. So I took my battery on the charger and left.

 

[RonD]

Seems like you are going about this the long way, a volt/ohm meter uses a battery with 1.5v to 9v and low low amps, so resistance test can be informative but it's basically a test for, is it connected, under 1ohm or is it not connected, high ohms, N/C

Follow the tests above, starting with battery voltage.
You are using battery voltage to test resistance.

Unhook charger and test battery, 12.2volts or lower means battery is damaged, if voltage is dropping with meter connected then one of the six cells in the battery has a short

 

[jeremyctry]

key off, check battery voltage, say it is 12.8v
Leave Volt meter's black probe on battery negative and put red probe on Alternators B+(large wire on back side of alternator).
Should see same volts, 12.8v, if not then Mega Fuse is blown, next to engine fuse box.
Move Black probe to alternators case, should see same 12.8v, if not negative cable has bad connection
Move red probe to battery positive, should see same 12.8v, in not then battery cables are not getting a good connection, check BOTH ends of each cable.

Now put black probe on alternator case and red probe on Yellow/White stripe wire, on alternator's 3 wire connector.
Should see 12.8v, if not 30amp fuse is blown, engine fuse box.

Turn on the key, engine off
Battery Light in dash should be on, if not then 7.5amp fuse in cab fuse box is blown, try fuse #11 or #15, but not sure on 2000

If it all checks out then start engine, Battery Light should go off
Voltage at battery should be 13.8 to 14.9v.
Above 14volts is "recharge" voltage, after 5 minutes or so it should drop to below 14volts or battery will be damaged
15v or higher will also damage battery

So this morning I finished putting it all back together and performed these checks.

key off, check battery voltage =12.91
Leave Volt meter's black probe on battery negative and put red probe on Alternators B+(large wire on back side of alternator).
volts = 12.88v,
Move Black probe to alternators case = 12.88v
Move red probe to battery positive = 12.88v

Now put black probe on alternator case and red probe on Yellow/White stripe wire, on alternator's 3 wire connector.
I see 12.88v

Key on battery indicator light comes on and goes off when I start truck.

Motor running
Voltage at battery = 14.25
voltage, after 5 minutes = 14.21

Now I'm not super exp with a multimeter, so I'm assuming that the .03 difference in my initial reading is user error(not getting a good contact with probes)

Am I wrong?
If I am wrong would .03 difference indicate a large enough problem to prevent charging?
If my battery was completely dead would that explain erratic speedo and abs light while driving?
Autozone said my Alternator is putting out 14.5, but I'm getting 14.25 is that significant?
Is that 5 minutes a hard rule or a rough estimate? (I set a timer to go off at exactly 5 minutes so I don't know what would have happened if I let it run for 6 or 7 min)

I've only got a couple more hours before I have to get ready for work so I'm probably going to have to bum a ride again. But I would love further feedback and suggestions on this issue or issues.

 

[RonD]

Looks like all is well.

Could take longer than 5 minutes for battery to get fully recharged so no, 5 minutes is not a hard a fast rule, but voltage was dropping so that is good.

When you/they test an alternator out of the vehicle the tester sends rotor full 9volts so alternator output higher voltage.
The way an alternator and its voltage regulator works is pretty simple.
An alternator can not generate any power just by spinning it
That's what the Battery Light circuit is for
When you turn on the key the Battery light circuit is sending 12volts, on the green wire, to the voltage regulator in the alternator, voltage regulator then sends 9volts to Rotor brushes.
Without this "startup voltage" the alternator will not, can not, start to produce power just by spinning, so no Battery Light = no alternator.
When testing alternators they send 9+volts to rotor
If battery light comes on when engine is running it means alternator is now a Ground, no longer outputting any power, well less power than the battery's current voltage.

When you start the engine the rotor spins and this 9volts creates a magnetic field
In the outside case of the alternator are 3 Field Coils, this spinning magnetic field generates AC Voltage in each of the 3 Field Coils.
AC volts are changed to DC volts and you get about 14.5-14.9voltsDC at B+
As Battery recharges the voltage regulator lowers the Rotor voltage to 7 volts or so which reduces the AC voltage and DC voltage at B+.
When you turn on headlights or Fan blower to high, voltage in vehicle drops so voltage regulator increase Rotor voltage to compensate

If your ABS or speedo are still erratic then you may have a bad wire at Engine fuse box.
Usually there is a smaller positive battery cable that runs to engine fuse box, this powers all the trucks electrics except starter motor

 

[jeremyctry]

Looks like all is well.

Could take longer than 5 minutes for battery to get fully recharged so no, 5 minutes is not a hard a fast rule, but voltage was dropping so that is good.

When you/they test an alternator out of the vehicle the tester sends rotor full 9volts so alternator output higher voltage.
The way an alternator and its voltage regulator works is pretty simple.
An alternator can not generate any power just by spinning it
That's what the Battery Light circuit is for
When you turn on the key the Battery light circuit is sending 12volts, on the green wire, to the voltage regulator in the alternator, voltage regulator then sends 9volts to Rotor brushes.
Without this "startup voltage" the alternator will not, can not, start to produce power just by spinning, so no Battery Light = no alternator.
When testing alternators they send 9+volts to rotor
If battery light comes on when engine is running it means alternator is now a Ground, no longer outputting any power, well less power than the battery's current voltage.

When you start the engine the rotor spins and this 9volts creates a magnetic field
In the outside case of the alternator are 3 Field Coils, this spinning magnetic field generates AC Voltage in each of the 3 Field Coils.
AC volts are changed to DC volts and you get about 14.5-14.9voltsDC at B+
As Battery recharges the voltage regulator lowers the Rotor voltage to 7 volts or so which reduces the AC voltage and DC voltage at B+.
When you turn on headlights or Fan blower to high, voltage in vehicle drops so voltage regulator increase Rotor voltage to compensate

If your ABS or speedo are still erratic then you may have a bad wire at Engine fuse box.
Usually there is a smaller positive battery cable that runs to engine fuse box, this powers all the trucks electrics except starter motor

Okay I haven't driven it again since yesterday. I was hoping that the Battery died due to loose connection and the battery only registering a 2% charge was the culprit behind my remaining problems. Now that the battery has a full charge I'm hopeful that my problems are resolved I'll take a chance and drive it to work today and stop at autozone just to have the battery tested. Its only 2 weeks old so I expect it will be fine but I like to check and re-check, and then have someone else check when possible.