mabrodis

I really hope someone has seen this before...happened twice tonight (first time ever happened)...I hear a horrible horn while at a friends house, we joke it's the neighborhood kids, well turns out it's MY vehicle...yeah WTF...it's a '96 4runner with the factory alarm. However, we never use the alarm, the FOB is actually not even on our keychains, always just lock and unlock with the key...and the alarm wasn't going off. It wasn't beeping, it was on solid, the parking lights and the horn, just on solid continuously. Got inside thinking it was the alarm (the alarm light next to the rear-window switch was light red), put the key in the ignition, turned it several times, i.e. to turn it off...)but it wasn't apparently the alarm, wouldn't go off. Disconnected the battery as fast as we could (side note, if your's do this, hold each horn in your hand, they will make no noise then, very helpful). Connected the battery up immediately and all was fine, vehicle started, haven't checked battery voltage, but never had any problem at all with it, starts perfect, etc...

I left the horns disconnected, drove home with no problems...about an hour after getting home I look out and the parking lights are on, wtf...go out and it's the same thing, everything just completely frozen, turning the ignition key does nothing (I didn't actually try to start it though, but from lock to on several/many times did nothing)...I disconnect the battery once again, although looking for a fuse also that would do the same thing, but not sure which one? ECU maybe? Anyway, after battery was disconnected, immediately held the wire to the terminal again and sure enough, all was fine. I left it disconnected, as I don't really want a dead battery tomorrow...

Anyone have any idea about this? We've only owned the vehicle a few months, has ~200K miles on it, never had any trouble. I just installed a Napa trailer wiring kit for it, correct kit for that year, plug-and-play, etc, which puts out a flat-4 trailer wiring harness, and have used it 3 times now to pull a boat. Today was the first time the boat went in the water, so vehicle was backed up until the back tires were maybe 6-8" in water, but no water touching anything on the body at all. Trailer was connected both times this psycho mode thing happened, though while it was doing it the second time I disconnected the trailer and nothing changed (first time we just wanted to get the damn horns off! )

As best I can tell it is alarm related, but not even functioning like an alarm, since it's not beeping/flashing, the parking lights are on solid and the horn is on solid. Maybe the alarm is semi-fried? One thing I did not try was while it was doing it's psycho mode to use the FOB to arm/disarm the vehicle...maybe that would have done something, not sure though, as turning the key in the ignition did nothing at all...

Any help or guidance would be *greatly* appreciated.

Oh, one other thing I just thought of...I drove back from the lake with dripping wet shorts...which obviously soaked my leather seat...is the alarm module under the driver's seat? Maybe enough water got on it to do something...that's a hell of a stretch, as I wasn't dumping buckets of water or anything, just had to hop in the water about waist deep to help guide the boat in...I wonder if that as anything to do with it...I kinda hope so actually, since atleast that might make sense...

-Mark

Wife's 4runner

Well, just taking a stab at it....get ride of your factory alarm. I am thinking of ditching mine. I like the locks-but the alarm is annoying as hell....

mabrodis

Not a bad idea...do you know if there is a fuse on it? I would assume so, but I don't recall seeing any "Alarm" fuse in either the engine bay fuse box or the under-dash one. I'd like to just kill power to it for now and see if anything else wierd happens..

Thanks,
Mark

mabrodis

Update: Happened again tonight while getting gas. Tried to turn off headlights and they were off, but parking lights on...switch did nothing...this time the alarm LED was not on...

However, I think I know the problem...since the only thing on these vehicles that can put on the parking lights other than the switch is the alarm right? Well that's my thoughts, so it obviously is alarm related, I decided to unplug the alarm ECU under the driver's seat. I couldn't imagine any water actually got on it from me sitting there with wet shorts...but apparently I was wrong. The floor was still wet and the alarm ECU still had water in it...doh! A bunch of the resistors and caps were oxidized pretty good...bunch of wet-ish goo on the board, etc. So I cleaned that all up with electronics cleaner, might reflow some solder joints if I need to, although most look pretty good.

So my guess is that will fix it...apparently I got ALOT more water on that alarm ECU than I ever would have thought...note to others, don't sit on the driver's seat with dripping wet clothes.

So, cleaned alarm ECU, will re-install tomorrow and post back whether issue is resolved...

Cheers...
Mark

Ron Helmuth

It would appear you have self diagnosed correctly. There has been some discussion regarding the rear window going down on its' own and apparently there is a TSB-Tech service bulletin-from Toyota regarding that and related to the Electronic Control Module (ECM) but your problem is slightly different and in an older vehicle(though still 3rd gen obviously) The short and easy quick for that is to leave the windows lock switch engaged at the drivers inside door to eliminate that occurring at random.

Thanks for sharing what caused the problem so we could all learn from it.

mabrodis

Update 2: It would appear the alarm ECU under the driver's seat was the problem. After removing it, cleaned throughly, drying, etc, and reinstalling I have had no problems at all.

I did stumble onto the fact that the engine will not start with the alarm ECU disconnected, I guess the vehicles without the alarm had a different wiring harness or maybe some dummy connectors in there. Everything would turn on just fine, but wouldn't kick the starter.

So, note to remember...don't sit on driver's seat when really soaking wet and/or pour water on driver's seat..