I am curious if anybody else has had this problem. I have tried to replicate it, but the problem only occurs sporadically and without much notice. Here is the problem with my 1998 Mitsu Montero Sport LS.

Two weeks ago my engine started to rev with a pulsing action, and the electrical started to go haywire. I immediately drove to my local electrical shop and they rebuilt the three-year old alternator. The truck worked for a day, then began to have symptoms again. (Although they were different symptoms discussed below.) The mechanic, who I trust, told me that the alternator was full of packed oil (leaking O rings, per most monties this vintage) and had to be rebuild.

The new symptoms include the oil and brake lights coming on, the ABS light coming on, and then the tachometer stopping. Shortly there after, all of the lights go dim, windows stop, air movement/fan stops, and all electrical goes out. The engine never stops, and I can drive it home, but there is no electrical on the drive home and usually (but not always), after I shut the engine off, it will not start again. Although sometimes, after awhile of sitting, it will crank. On a rare occassion, however, it will allow me to start it again after the engine has been shut off.

I have tested the new alternator (it is good) and the battery (it is good, too, but is drained and I usually have to jump the battery to start the truck again), and the ignition switch is good, too. I thought perhaps there was a loose ground fault (my battery and oil lights have been on faintly since I had the new alternator put on three years ago), but they all appear solid. In short, the electrical situation is normal, then all...well, you know from the title of this message what happens next.

Any suggestions? The battery is charging in excess of 12 volts, the ground faults seem to be in order, and the alternator is like new.

Thanks in advance for any help. I am about to take it back to the electrical shop, but thought I would ask here in the case that I am overlooking something obvious.

Best,
flyhotair

 

it sounds like the computer?? costly. my moms dodge stealth(mitsu 3000gt) did pretty much the same thing, but there were times, while she was driving, it would die and have to sit befor it would start

 

you have a wiring issue somewhere in the ignition system, or corrosion in the harness around the fuse block under the hood.do your battery terminals have alot of corrosion on them? or have they in the recent past?? corrosion can set in anywhere in electrical wiring around the battery. i would start there.

 

Thanks jwhiteh and jbgrules for your diagnosis. They have become my plan B should the current fix not work.

After my post the problem replicated itself when I was out driving so I took the truck to the same electrical shop that rebuilt my alternator two weeks ago. The owner of the shop could tell that the alternator had a bad diode in it just by listening to it. They are replacing the alternator and we will try it again. I will pick the truck up later today.

I did not suspect the alternator, having just had it rebuilt, but I am hoping that is the case. I will provide an update when I get it back later today.

Thanks again for your posts.

Flyhotair

 

My mechanic replaced the rebuild alternator installed two weeks ago with a new alternator (at his cost, even!), and all is well. So I am back on the road.

Love the Montero Sport, but its electrical system has been problematic since the day I bought it!

Thanks for your help.

flyhotair