Haven't made a intro thread since I am helping out my Mom with her truck...

Truck is a 2000 Ford Ranger 2.5L. I just replaced the battery and alternator with new units that have tested perfect so far. When I removed the stock alternator there were 2 wires coming off the 10mm nut. A fat red and a skinny blue. The blue wire came straight out and the end without the eye terminal is heat rotted and falling apart. I have NO CLUE where this wire came from. All other wires are good. After searching the forums I yanked the battery and have checked all the wiring. I cannot find where this blue wire was connected. Any clues??? Looks like it dropped down under the motor....

Any help would be great! Thanks in advance!

 

do you have a chilton's manual for your truck? It would tell you.

Honestly I am still in bed too lazy to go look at my truck and tell ya right this minute, but I bet the blue wire was a ground?

 

Okay just looked. My truck is an 04 4.0 so it's apparently different. I had about 6 wires coming off of my alternator.

 

I've got a 3 wire connector in good shape that joins a harness with a single wire push connector in good shape too. Behind the alternator on the stud with the 10mm nut on it there is a fat red and a skinny blue. Don't have a Chiltons or a Haynes for this truck. That may be the next step. Finding a wiring schematic for a 2000 Ford Ranger 2.5 is way more difficult than my 24 yr old brother saying "just google it man..." Dill-hole couldn't put gas in a car if it meant saving his life.

 

In my experience ,over multiple vehicles and platforms, there should only be the fat red wire coming off the stud on the alternator. That wire goes directly to the battery.
Anything else has been added by the owner.

 

Looks like someone added the blue wire. Maybe for some lights, radio, ect.

My truck has 3 wires from the connector, another connector (1wire), and a big wire (Black with orange stripe) from the stud to the Power Distro box/Battery.

Do you have a pic of your Alternator and wires?

 

See that's the funny thing. No one in my parent's house has any mechanical knowledge besides me. That's why I get called to help prevent labor costs. LOL! My mom bought this truck brand new and hasn't let anyone touch it besides me. It has 134k miles and has only had the oil, air and fuel filters changed. This is the first time I've ever had to touch the alternator. I am thinking of taking the front off and doing the timing belt while I'm at it since the miles are up there. She uses it daily and drives maybe 200-250 miles a week now since she has retired. Used to drive from Tucson to Prescott every weekend and all the way out to Caldwell, KS once in a while. Nothing has ever been added like lights, stereo or anything of the sort. Weird truck since it's a twin spark-plug motor. Anyway....

Picked-up a Haynes manual since it's the only one I could find. Nothing mentioned or pictured about a blue wire. I've tried to follow it to a source but cannot find a damn thing. Just wondering where this stupid thing could have come from.