less than 4 years ago I had to replace the alternator on my 95 montero at about 120k miles.I bought the vehicle used at 100k and this appeared to be the factory original alternator. I did not go to an auto store to buy a new one , instead I took it to the shop of a local company that rebuilds electrical components for heavy diesel and commercial equipment. All of our diesel equipment is running on their rebuilt alternators and regulators without fault. Cut to the chase ...that one lasted about a year before the lights on the dash (and headlights and taillights) started the pulsing again. Replaced with bRAND NEW heavy service alternator from auto store, and about 18months later the pulsing of the light, thus of the current flow is back and slowly getting worse. ANYONE have any idea what this is all about. Am I just unlucky with alternators or is it something with the car??? Dont want to spend another $250 on new alternator without findind some solution.

Have you replaced the voltage regulator when replacing the alternators? I'm not sure if it's integral in the gen II alternator or if its a stand alone module. I'd look to see if anything is wrong with it.

Have you found a solution yet? I have a '96. We went through 6 alternators in 2 years. Most were put in by the dealer after failing in less than one year. Longest lasted 10 months, shortest less than 2 weeks. Current alternator has been in the car for over 1 year (so it is my problem now). Just today while driving around the brake, auto-transmission, and battery lights came on. We headed home, and the compass started acting up when almost home. Battery voltage was at 12v with the engine running. Looks like I get to by another alternator.

Has anyone else had similar problems with the alternators? Any reason why this should keep happening?

Any insight would be highly appreciated.

Thanks

Not sure of the type of engine in your vehicle but if it is the 4D56 engine look for the following: The power steering fluid bottle should be positioned right above the alternator. During driving engine vibration causes the fluid to leak. And guess where it falls.. right into the alternator. I know this because I had the same engine in My L200 and went through like four alternators in one year until i discovered that the leaking fluid was the problem. My solution was to get a different type of power steering bottle and mount it to the front of the vehicle away from the alternator. After that conversion I was good to go.

Like I said not sure if your engine setup is the same but if it is you may want to look into that.

I have a 95 Montero and my alternator died every 9 months. It did this twice and both times it was due to oil in the alternator. I googled this and found out the head gasket on Monteros is notorious for leaking oil. The oil falls past the alternator and gets sucked into it. This eventually kills the alternator. A cheap and easy fix is to put a metal guard between the leak and the alternator. I'm pretty sure even an aluminum pie plate positioned correctly would be sufficient.

Well, 'notorious' is a pretty strong word to use. I'm heavily involved with mitsu 4x4's and from the probably hundreds of Montero, Montero Sport, Dodge Raider, Mitsu Pickup owners I've been in contact with, I'd have to say the the 3.0L and the 3.5L don't have "notorious' head gasket issues. The only time I recall a head gasket issue was where the heads were improperly torqued resulting in a seal failure but you wouldn't get oil outside the engine.

The other oil issue these motors have is the valve guide seals wearing but you get oil out the exhaust not on the engine.

Other than that these mitsu v6 engines are pretty solid motors.

Guess it's not notorious then. When I looked it up there were quite a few people complaining about oil in the alternator.

My Montero has the valve seal problem, Im guessing, since it puffs.

It is a great motor though. I hear it's not hard to get 300K on it.

its certainly not notorious.
Use MITSU parts, not aftermarket junk. and fix the leak on top of it. Your alternator will last forever then (mines at 204000 miles).