Hello Ranger Forums,

I have a 1993 Ford Ranger XLT, with 458,000k miles ( yep! ). I've never tried to get help with my ranger, because it's just never needed it... until now. So this is my first post here!

The day before yesterday my friend needed a jumpstart. We connected the cables and waited for a while but his car wouldn't even turn over. So I took my battery out, and put it in his vehicle. We got it started, and put his back in. His problem was solved. He put my battery back into my ranger backwards and connected the terminals incorrectly. We switched it around, and the ranger ran fine, until I noticed the battery wasn't being charged. I made my trucks final trip home from work tonight with almost no headlights.

I don't discount the idea that very crucial electrical parts of the truck may ( and probably were ) damaged.

Everything on the instrument panel functions well and there are no noticeable problems other than the truck no longer charging the battery ( or the battery no longer accepting a charge? )

Could you guys please help me troubleshoot what could be the problem? I have two jobs, independent, and I'm a full-time student. So I would love to think it's a moderately simple fix that will allow me to ride the ranger through to it's final glory :D

Infinite thanks!

 

I would get truck started and check voltage at battery, should be a little bit over 14 volts, if not take alternator out and have checked

 

Check the voltage at battery with engine. Running and you will see the alt is probably not charging, maybe fusible link

 

With battery connected test its voltage, key off
Should be about 12.1v if close to dead, should be 12.5v or higher fully charged.

Now leave meter connected to Neg on battery and test voltage at B+ on alternator, this should show same voltage as battery, if not a fuse or fusible link is bad, these can be in the Engine compartment fuse box OR attached to the Starter Relay on the fender well.
B+ is the bigger terminal on the back of the alternator, it has the bigger wire(s) attached.

If B+ voltage is good then pull off 3 wire connector on alternator and check the Yellow/White wire(usually center wire), it should also show battery voltage if not fuse is blown.

On this same connector is a Light Green/Red wire, this is the ON/OFF switch for the alternator, it should show Battery Voltage when key is ON, this voltage comes from Battery Light in Dashboard and/or Volt meter in dash.
If no voltage with key on check fuse.

If every thing checks out as good then voltage regulator in alternator is bad

 

thank you for the detailed responses. They were extremely helpful. I went to the AutoZone next to my work and had them charge my battery. After an hour I borrowed a voltmeter, and started on the battery first.yielded 12.56. then from the negative terminal to the bolt on the back of the alternator and that yielded 12.56 as well. Afterward the yellow and white cable on the connector which was on the left side and that yielded 12.56. Afterward with the accessories on the green and red cable also yielded 12.56. I reached the end of your post and was assuming it was the voltage regulator. At that moment one of my friends at the AutoZone came out and told me that "you could have just tested it with his utility" , so to double check we hooked it up and his also said the voltage regulator is bad. The new one is 60$ at my AutoZone, so I figured I will go to my local u pull it junkyard and grab a couple for 10 bucks instead. Any thoughts? I appreciate the directions because I like to learn how to diagnose problems. I'm a computer technician XD, must be in the blood!

 

Voltage regulators are solid state now(no moving parts), so used is fine, as long as they are not blown as well, lol.

Yes, reversing polarity at battery could have damaged the voltage regulator, you may have some other issues as well, so be watchful of any odd behavior from electrics in the system.

Just for future reference, you aren't really suppose to use your "computerized" vehicle to jump another vehicle, voltage surges are common and can damage electronics.
Best method would be to disconnect your battery from vehicle before using it as jumper battery.
If vehicle that needs a jump still doesn't start then it's battery is bad, internal short(most common) or wiring in vehicle is bad/loose/corroded.

Running jumping vehicle at 2,000rpms while trying to jump is not a good idea any more, it ain't the "old days" any more, lol.
There is a reason the other vehicle won't start on it's own, could be just that the lights were left on, if that's the case then disconnecting your battery and hooking it up will get the dead battery vehicle started, if that's not the case then what wrecked that cars charging system can spread to yours if hooked up to your system electrics.