I've seen many reports of aftermarket alternators for Montero not being reliable (long lasting). When I had to replace mine (due to oil from camshaft seals) I went for an OEM replacement from one of the online Mitsubishi Parts dealers. It was more expensive then an aftermarket, but I just did not want to have to keep swapping alternators with cheap knockoffs. In addition to that, since none of the local shops had the aftermarket alternator in stock, the delivery time for OEM was just about the same as the aftermarket ones.

 

Yeah I'm leaning towards going with OEM Mitsubishi - read a lot about issues with cheap diodes in off brands not playing nice with the charging system.

 

OEM Alternators are not cheap!.

Hunter did you buy a new one or a Mitsubishi rebuild?

Alternator part number for a 2002 3.5 XLS is a M350608D

New, not remanufactured, $721.97!!!
https://mitsubishipartswarehouse.com...&siteid=214581

Here is a remanufactured from Mitsubishi website (so I assume rebuilt by/for Mitsubishi?) for $218.28 plus core and return shipping (need to enter part number M350608D). I bought a lot of parts from this company, very good to deal with for me. I will call them tomorrow
https://www.mitsubishiparts.com/oe_parts_catalog.html

Here is an OEM one for $230.41 with no core. Not sure if reman or brand new:
https://mitsubishiparts.net/parts/20...ion=ALTERNATOR

Here is an OEM one for $225.21. Not sure if reman or brand new or if core charge and return shipping is involved.
#M350608D: Alternator.

Here is an OEM one for $199.21. Not sure if reman or brand new or if core charge and return shipping is involved.
https://parts.com/index.cfm?fuseacti...E5L-ALTERNATOR

 

I bought mine new from Mitsubishiparts.com. It was somewhere in the neighborhood of $250 from them, while local dealer quoted about $700 for the part.
I did not find any remanufactured alternators for my Montero, except the aftermarket ones, so I stayed away from them.
Surprisingly my alternator order did not require a core return. I put the old alternator on the shelf and if some day I run out of things to do, I plan on rebuilding it with the rebuild kits form Mitsubishi.

 

Thanks Hunter. I will call them tomorrow. That is the place I got a lot of parts from, very good experience. They list it as reman oddly with a core.

 

I bought a Mitsubishi alternator M350608D for $230.98 from a dealer near my work with $20 core charge. It came in a Mitsubishi box and there is a Mitsubishi sticker clearly labeling it as remanufactured.

On the Montero Sport, the alternator can be pulled thru the passenger wheel well after taking the tire off and the rubber flaps.

One more problem solved. Not sure why the alternator died post engine rebuild as it was not a problem prior to the spun rod bearings.

 

I have a 2000 Montero Sport LS and I have all of the same problems that you have right now I have replaced the starter and the battery as the parts store tested the alternator and stated it was fine and did a load test on the battery stating that it was in need of replacement so I put the battery in and everything works great the brake light and battery light went off and the vehicle ran perfect for one day until the battery ran down and all the lights came on the vehicle stalled so I convinced the part store to exchange the battery as it was only 12 hours old and just as I suspected everything works great for another 12 hours until the battery died because the vehicle was basically running on battery power and the alternator was not consistently putting out voltage I found that it was covered in oil which as we all know kills the alternator. The obvious solution is to fix the oil leaks and put an alternator in otherwise it'll just happen again but if you have a 16 year old car with 185000 miles on it who wants to spend that kind of money and time I know I don't I did some research and found that Motor Parts of America (MPA) Lakes a oil spill Shield it's just a piece of plastic that they mount on all of their remanufactured or new alternators for the Mitsubishi Montero and I suspect other models and makes but this is the problem and your solution I promise you because I had spent countless hours and too many dollars getting to this point so I'm going to buy that alternator and still Shield tomorrow here is the link to the YouTube video hope it helps

https://youtu.be/RhFoFSe1A3U

 

I had the same problem that you are having somehow the alternator stops working the the engine warms up and i remember taking it off, taking it to the part store and them testing it for them the alternator was always reading good.

I told them i dont care if you test it because they test it for less than a minute my problem used to show after 10 or 15 minutes.

This trucks dont play good with aftermarket alternators so my best advice would be replace it with a mitsubishi one or make them replace it because it'll keep happening.

Trust me and when you get one that work right light gonna start dimming cuz those alternators just dont play good