Problem child '06 SR5 - alarm randomly going off while driving?

[pyrakel]

Hello all,

Happy to be here and a part of this forum! This is my first thread.

To start off with, I'm a shadetree mechanic (I build classic cars) helping a friend with his recently-acquired '06 4Runner. It's a V6, 2WD, nothing fancy but extremely clean. 125k miles which is super, super low miles (which is why we went after it).

Anyways, this thing is trying to be a problem child and I am determined not to let it be so!

When we went to look at it, the back hatch would not open. However, the guy showed us that when you disconnect and reconnect the battery, the latch works again (briefly). That to me said electrical issue (fuse, loose connection or something) BUT I have been reading up online and it seems that most people are able to solve this common problem by taking the latch apart and lubricating it really well. True? And if so, why would this work when disconnecting the battery works as well? Just kind of a confusing solution to what seems to be an electrical problem.

Recently (this week), the car's alarm has started to go off at odd times. Most recently, it went off while my friend was driving :suspicious: I haven't seen a lot of posts on this happening so apparently it's not that common. Haven't looked at it yet but I am fairly certain that this is a stock alarm system that hasn't been tampered with (though I will double check) - so is there anything else I should be looking for?

The battery is less than a year old. No other known electrical issues though I am wondering if the latch issue and alarm issue are maybe related?

Any advice would be wonderful. Thanks!

 

[supersaiyan96]

Could be a problem with the pressure sensor in the alarm. Mine did the same thing when I first got my 04' a month ago. I ended up disabling the alarm (who takes car alarms seriously these days?) by pulling the fuse for it. If it's the usual port-installed alarm (arms and disables using the stock Toyota key fob) it's easy to disable. You just have to pull a 15 amp fuse by the steering column.

http://www.toyota-4runner.org/4th-gen-t4rs/227417-factory-alarm-horn-issue.html#post2508375

 

[riceandpho]

could be a weak battery. also on the alarm, is it factory or aftermarket? if its aftermarket , could be a bad ground, or bad wiring job.

 

[pyrakel]

Hmm, pulling the fuse could be a last-ditch effort I suppose.

The battery checks out fine, at least by my multimeter's standards.

Maybe I'll see if I can do some poking around in the underdash wiring to see if anything looks fudged up. I don't think it's an aftermarket alarm though.

 

[gm350reratliff]

could be a weak battery. also on the alarm, is it factory or aftermarket? if its aftermarket , could be a bad ground, or bad wiring job.

That's what it sounds like to me as well. Definitely some loose connections somewhere. As far as the rear hatch, after the battery is reconnected perform the normalizing routine and see if it works after that. If not, I would start trouble shooting in there. Could be a loose connection as well.

 

[pyrakel]

What is the normalizing routine? I hadn't planned on disconnecting the battery or the rear hatch wiring at all (just pull out, clean with some PB Blaster, grease with white lithium, reinstall) because I was not quite sure if it would then have to be reset somehow.

 

[BlackWorksInc]

Sounds like you have an aftermarket alarm installed on the vehicle, probably a cheapy "Port/Dealer Installed" unit. Factory anti-theft deterrent won't trip while you're driving unless you've got some seriously weird electrical issues tricking the vehicle.

 

[riceandpho]

any update?

 

[pyrakel]

Yes, just got to it last night actually. The alarm is an aftermarket unit, though it doesn't appear to be a hack job from what I can see up under the dash.

My friend hasn't had a problem with the alarm going off since it happened the one time, so I guess that's no longer an issue (until it makes itself an issue again).

I think I will start a new thread about the trunk latch issue for better visibility (since this one's title is just about the alarm), but in short, last night I took it all apart and sprayed the hell out of it with PB Blaster and then greased it with white lithium. Put it back together and now it will open 5-ish times before it quits working. Once it quits working, you have to unhook the battery, then hook it back up and it'll work again another few times.

When you hit the button for the back hatch, you can hear it click (kind of a relay sound) before the electric motor actuates and releases the hatch. When it is not working, there is no sound from the electric motor and there is no click from the switch. So I am wondering if maybe it's the switch itself that's going bad, not the latch. Not terribly familiar with 4Runners, but since there's no button inside the car to pop the hatch, there's not really a way I can think of to test it. If there was a button elsewhere, then I could just hit that and if it works, that would verify that the problem is in the switch on the hatch itself and not with the latch.

Any ideas? Again, I'll start a new thread just so others who likely have had this problem can see it...