2000 Explorer XLT 4X4 4.0 SOHC V6, 83,000 miles......losing voltage and truck stalling. Replaced alternator and battery. Ran for 3 days then stalled and would not run again. Alternator is reading good as is the battery but will not hold or read a chage. Still will not run at all. Checked all fuses and wires and all are good. At this point I have no idea what it might be. Computer perhaps, or a short? Anyone with any idea please let me know.

 

Sounds like it ran good until your new battery went dead.

When you installed the new battery did you connect a voltmeter to it and check to see if it's receiving around 14 volts from the alternator?

 

Ya we tested the battery at a full 14 after we put it in. It still reads 12 volts even though the truck won't run. We cant get the truck to run again so we cant test how much is coming from the alternator though. But as it sits the battery holds 12 volts.

 

Whats it doing now? Cranks, but wont start or wont even crank? Will it jump start?

Do you hear the fuel pump when you turn the key to run?

 

I dont hear the pump and it wont even crank. Wont jump either. Stone dead.

 

If you don't hear the fuel pump and the fuel pump relay is good, you might check the inertia switch to see if it tripped. Should be around the passenger side kick panel.

 

If the battery & battery cables are in good shape & NOTHING turns on with the ignition switch, i'd check the maxi fuse that feeds the ignition switch.

Have you got a good set of wiring diagrams such as the Ford "electrical & vacuum troubleshooting manual"?

I dont have wiring diagrams for a 2000, so thats about all that I can tell you.

Edit. There is probably a fuse between the ignition switch & the starter relay. If the maxi fuse is OK, check for voltage at the fuse with the key at start.

 

I will look for the guide. I just tried starting the truck again and the starter will klick when turned to ignition just the same as if there isnt enough charge but the battery still reads 12 volts. Checked fuses again and all are good. Could this possibly be computer?

 

No,it's not the computer.
The click you are hearing is the starter gear being shoved into the flywheel.
Check for a clean tight connection of the battery to starter cable at the starter.

And check the negative battery cable for a clean tight ground.

 

You state that the battery shows 12 volts, but have you checked the voltage when your trying to engage the starter. I suspect that it drops to far less than 12, because it sounds like your battery is dead. Do you have a battery charger? If so, first disconnect the negative cable to the car and charge the battery to obtain a full charge. This will help to diagnose the real problem. If the battery will not charge, there's your problem. If the battery will take a charge, the next question is does your multimeter have the capability to read DC amperage of at least 10 amps? If it does, then configure the multimeter to read amps and connect it between the Negative post and the cars negative cable. Make sure that everything is turned off and all of the doors are closed. If the reading is more than around 1/2 to 3/4 of an amp, then there is something pulling power that shouldn't be. If something is pulling too much current, you can start pulling fuses one at a time to find the problem circuit. Then you can narrow down the culpret by looking at the components that circuit supplies. If nothing is pulling too much current, then you can hook up the negative cable to the battery and begin trouble shooting the reason that the engine will not run. If you have a charged battery and still hear the click but no turning over, start looking at the starter solenoid/relay and possible dirty connections / loose wires.

 

appreciate it i will try all of that rite now

 

Tried a 3rd alternator in and charged the battery up to 12 volts. Truck turned over, ran for 5 minutes, then shut off. Repeated the 5 minute running then shutting off process 3 more times before the battery was dead. Guessing possibly a short between the battery and the alternator? I am looking to bypass the curcuit and power straight from the battery to the alternator. I thought a fuse but all of the fuses are ok. Ideas on what to do next?

 

When you take the negative cable off and put it back on, do you have any heavy arcing? If there's a true dead short, I would expect some heavy arcing. During the 5 minutes it was running, what was the voltage?

 

voltage stayed the same ... testing the battery as it ran charge went down , no arcs. Got guide for truck and checked all electrical and found no problems; all fuses are good as are wires. What now?

 

So while it was running, the voltage stayed at 12 volts and dropped. In that case the alternator is not charging at all. If you take the alternator to a parts store, does it bench test OK? When you charged the battery with a bench charger, how long did it go, and at what charge rate? If it's completely down (which is how it sounds), then it's going to take around 8 to 10 hours at a 15 amp charge rate to get a good (close to full) charge. When you checked the wires, did you check for continuity and resistance from one end to the other of all of the alternator wires? There are fuseable links and fuses as well as wire breakage and corrosion that can cause issues. Also, be sure to check the plug where it goes on the alternator. Sometimes the female connections can become too open and loose and cause problems. I suppose one other possibility could be the ignition switch as the back voltage to energize the field probably goes through it, but that's not likely (you could look at your schematic to verify the path). Also, it's possible that the battery is bad. I realize that it's new, but this can happen. Do you have a load tester or know anyone with a load tester that you can check it with after it's charged? If not, you may find a parts store will do this for you.