2001 Pathfinder, New Battery, 2nd New alternator, No charge

[native74warrior]

I have a 2001 Pathfinder LE 4x4, made 06/00. Alternator went out and battery went out, replaced both. When alternator went out bat. light and a/t light came on. Had battery tested, bad replaced it, had alternator tested replaced it. Started it up no light and started fine. 12.56 volts at bat. with engine off, with engine running 11.5 at bat. Did checks according to FSM all checked good, said alt. was bad. exchanged the alt. and had the one they gave me bench tested at same store checked out good. Store regular chain store, do not want to say the name, not sure if I can. Installed, checked volts at battery 12.56 with engine off, 11.7 with engine running, Did FSM checks again (just to be sure I did not miss anything) good. Did ohm's checks on wiring by the diagram good, took wire harness apart checked wires from alt. to battery and all others even took fusible link and fuse box apart (E60) to fully check wires, all again checked good. Everything is saying the alt. is bad so before taking it back and spending the extra money on a dealership one, I wanted to post and see if anyone has had this same issue. I researched previous post and did not find any exact issues that I currently have. I am at a loss, I have been working on cars all my life, I am not an expert but have no problems fixing any issues including electrical, but this one has stumped me. Can two aftermarket alternators be bad? I read our trucks are finicky but this much. What am I missing?

[Rugger56]

I heard of this before. I'm not familiar with the procedure to fix it, but it has to do with forcing the alternated to develop a "Field Current". That's the DC current that sets up the magnetic field that gets the alternator to generate power. With out that field, the alternator spins, but can't make electricity. It could be that there is no connection from the battery to the connection for the field.

[native74warrior]

I will research that and see what I come up with. Thanks for the info.

[yeldogt]

Yes .. two alternators can be bad ... the aftermarket alternators from the big national chains are junk. Unfortunately, the unit in the pathfinder is not widely available. Hitachi makes it ... it's very hard to find the OE that been rebuilt by Hitachi. They may say Hitachi .. but you have to make sure it's been rebuilt BY Hitachi. most are OE units that failed and rebuilt by others .. really they are only fixed and not rebuilt. The rebuilt is 2310M-3W400RW

[Rugger56]

Here's a link to testing the field current: https://itstillruns.com/test-alternator ... 15682.html

[Rockwood]

There is a fuse in the underhooddfuse box next to the battery that is for the alternator - is it good? Also, the output cable from the alternator goes to a bolt in that fusebox. Test your alternator output voltage at that bolt and see what you get. It may be higher than at the battery.

[yeldogt]

It's not very hard to figure out. You should be getting upwards of 14 volts with stuff running .. under 12 the battery is trying to power them. The battery is there to start the car and provide voltage stability ... sound like the diodes in the regulator are and .. any noise?

As I said above this is a common problem .. and has been for many many years. I run a fleet of cars for my business and get the fleet magazines ..... junk electrical parts from China and poor rubber parts from India are a constant topic. Years ago, every area had a motor shop .. that fixed starter and alternators. As the products got better (failed less) and new from China was cheaper vs fixing the OE .. the shops closed. The profit on alternators is very small ... if you look inside most of the rebuilt generic parts .. they use many of the same parts regardless of the application. Even the new copies of popular vehicles have common innards ...they cost so little it's cheap for the stores to offer lifetime warranty.

IMO -- better to get a used OE vs buying cheap aftermarket. With three 02 LE's -- two of them went over 200k and still had the OE unit when I sold them ... my current one needed one at 80k. I bought the one above -- unfortunately, no easy substitute .. it was around $300. It's a pain to replace .. so I did not want to do it again

[nickelghandi]

Check out my thread here: 2-day-battery-drain-out-of-ideas-t618534.html


I had the same problem with aftermarket alternators. I am not saying that yours definitely is bad, but mine was.


After countless checks, replacing the alternator for the 3rd time fixed it.