Here's the situation:
This montero (1994) has been having problems maintaining idle for a while... sometimes it will idle, but most of the time it will cut off as soon as you take your foot off the gas pedal. It sat for about a month or two without being drivin and when I went to crank it, it was dead. When I went to jump it off, i was in a hurry and did a bone head thing... I reversed the jumper cables. When I realized what I did, I hooked them up right and cranked it up. The idle problem was the same, but as I revved the engine up, the sound from the radio cut out and it would come back on as the rpms dropped. If I revved the engine higher (@ 3k), the doors would lock!!. I noticed a small puff of smoke from behind the radio as well. I cut it off... Several fuses were blown and replaced. I did also notice that the fuseable link for the alternator was blown and haven't replaced it yet (no dealer), but did jump the terminal for a second to see if that made any difference. The speakers now hum and the door locks hum if I rev the engine. Obviously its from jumping it off the wrong way, but is it that the alternator is now bad and somehow sending excess voltage to the electrical system? Any ideas on how to check the system out? Thanks guys for any help, including help with the idle problem.

my wife did that with my '92 when it was only about 9 months old...FRIED the computer...had to replace it. <img src="/forums/images/graemlins/barf.gif" alt="" />

any way to test it? It still will crank and run... seems if the computer were fried it wouldn't...

If it does not hold an idle when warmed up it is most assuredly the Idle Speed Control Motor(ISC). It is one of the most discussed items on this board. Here is a good link as to how to test and/or clean it.

ISC Link

As far as your other electrical problems, it sounds like you have a lot of them due to the "reverse jump"

Not entirely true:



Got 180 miles before the connections to the wire harness fried themselves apart (or maybe the wet mud completing the cicuit finally dried up <img src="/forums/images/graemlins/shiner.gif" alt="" />). This of course was preceded by a very rough running, occasionally stalling and dying engine.

anyone have any ideas on this as in where to start testing? Seems that the alternator has something to do with it as the electrical problems aren't there when the montero isn't running... when it is running, things like the windows going up and down much faster than normal happen.

Well if you find a good dealer they will have a wire harness tester. Electrical grimlins are the worst kind <img src="/forums/images/graemlins/frown.gif" alt="" /> <img src="/forums/images/graemlins/evil.gif" alt="" />

Unfortunately, our dealer here in athens closed down a few years ago... closest one is about an hour or so away I think and the monty just won't make it that far I'm afraid. Guess I'll start with the ECU... found some testing procedures in my repair manaul (dug it out of moving boxes last night)

Mine had similiar stalling issues, it was the ISC motor. Not sure about the rest of it. I paid about $325 for a new one from the stealer.

Can you drive it to an Autozone or equiv.? They can check out the computer for problems for free. Also test the alternater.