2002 Ranger Edge 3.0L Alternator Intermittently Charging Cant Find the Cause

[Brichard2440]

Aloha,
I bought an 2002 Ranger Edge 3.0L at the Pearl Harbor Abandoned Vehicle Auction that I've been slowly pulling out of the grave. I ghot it running pretty good then all of a sudden the dash battery light came on and sure enough the alternator quit charging. I replaced that 1 and within about 10 miles of driving the new alternator failed. The 3rd one is working intermittently. I read the forums pertaining toi similar issues which led me to check all the grounds, etc. I haven't actually tested the fusible links but the insulation on them looks to be intact. The thing I noticed that is consistent with the intermittency is that at first startup the alternator is charging as it should then shortly after reaching normal operating temp the alternator stops charging. Also when low idling it charges fine but when the ECU increases the idle to engage the fan clutch the alternator stops charging then starts charging when the idle slows again. That is consistent as I watched it over a 20 minute period and that cycle happened several times. I am thinking someone monitoring the problem will know what the likely culprit is based on intermittency being consistent with idle fluctuations. I appreciate any and all feedback.
Mahalo!

 

[franklin2]

02 Ranger Edge 3.0L Alternator Charging Intermittently

Aloha, I bought an 2002 Ranger Edge 3.0L at the Pearl Harbor Abandoned Vehicle Auction that I've been slowly pulling out of the grave. I ghot it running pretty good then all of a sudden the dash battery light came on and sure enough the alternator quit charging. I replaced that 1 and within...

www.therangerstation.com

 

[Lefty]

I bought an alternators for my 3.0. It failed. I took it back to the parts store and that one failed too. It's probably not you, or your truck.

There is also one very simple way to test it. The rear of a healthy alternator throws out a powerful magnetic field while the engine is running. It should suck the tip against it and hold it tight.

And if you get another alternator, put in an uprated aftermarket voltage regulator. It will charge the battery faster.