Mine did that, found out my battery was going bad. Changed out the battery and when hooking it up get blasted by the alarm. Since it was active when power was pulled.
It just started back up. Scared me when it went off in my face and I finally jumped in and reset the alarm. No issues ever since.

 

I bought a new battery last month, last night the alarm went off three times. My neighbors were not thrilled. =( If it bridged the two latch release wires together, would that cause the ECU to think the hood is locked? Then if it got grounded somewhere in the loom, it wouldn't set the alarm off?

 

The hood switch is open when the hood is closed. So connecting the two hood switch wires would signal that the hood is open, which would prevent the alarm from arming. If you disconnect the hood switch, by default the security system will always see the hood as closed.

Check the tailgate latch switch. Same deal - the switch should be open when the tailgate is closed.

Dave

 

The hood switch is open when the hood is closed. So connecting the two hood switch wires would signal that the hood is open, which would of course set off the alarm. If you disconnect the hood switch, by default the security system will always see the hood as closed.

Check the tailgate latch switch. Same deal - the switch should be open when the tailgate is closed.

Dave

This info is incorrect. Actually the opposite is true.
Jumpering the hood switch harness will signal that the hood is always open and PREVENT the alarm from arming and thereby never setting off the alarm. This is a common method of resolving random alarm issues. Of course it does not fix the root cause issue.

 

I'm have to he same situation so I'll use this thread. I've read all other posts regarding this issue, but nothing has worked so far. I have disconnected the hood switch (but not the tail). I checked the B-CAN codes and I just get "no" on the dash. One service manual I checked for 2008 (I have 2007) says that there is a way to get a reason code from the flashing alarm light -- I'll try that next.

A couple of additional clues for my situation:

• Just before the alarm triggers I hear a relay snap.
• After I deactivate with the remote and unlock the car, I cannot relock it with the remote.
• The trigger of the alarm takes some random amount of time, sometimes more than an hour.
• I have a new battery.

Any additional thoughts from others? I'll spend some more time on this tomorrow. Thanks in advance.

Brad

 

checked for 2008 (I have 2007) says that there is a way to get a reason code from the flashing alarm light -- I'll try that next.

Lots of folks [including me] would benefit from directions on how to use these codes!!

 

I am also just dealing with this issue with my 07 Ody...

About a year ago, the alarm would go off, randomly. Searched and found that the hood latch micro-switch was a major problem. Easy fix, Disconnected...

Lasted till today, alarm started to go off randomly again... Checked the hood switch to make sure no one reconnected and was still disconnected.

Searched around again and some people had said that the rear hatch also has a micro-switch that was made flimsy and I disconnected that also. I took the little panel over the latch mechanism off (small 5x5 square plastic, bottom center of rear panel) looked at the whole latch could see two sets of wires and connectors at left and right top area. Also another wire connector more towards the bottom closer to the "latch hook" I disconnected that one and the rear interior light now is off, and the idiot light for the rear hatch is off on the dash. BTW that micro switch was not held in place with much, other than two plastic plugs and they both broke off so I twisted the switch out. Now my rear hatch lights only work via the manual switch and the "idiot" light on the dash will not show that the rear hatch is open. No big deal for me...

I thought that would fix it, but it did not. I was bummed...

So back to square one, went down to the local pep boys type place and had them load test my battery, everything was fine, battery good, AMP good, they even took the cables off the terminal and cleaned them with a terminal brush tool... Not the battery....

So I sat in my car, quite as can be, armed the system and waited a few minutes passed and the alarm would go off, no noise, no click, nothing to note that might cause the thing to spontaneously go off... I though about the 4 door switches for the lights, and went around pressing and making sure there were no hangups or out of sorts on them. They all looked fine, rubber boots intact, springs strong and smooth actions.

So sitting in the car again I though, hmmm the alarm is probably triggered by something that would indicate a door, hatch, hood was open. I have a few young kids and they always play with the over head lights. So I keep the master switch for the interior lights always off. so even if they play with the overhead lights they are never on.

Let me see what the interior lights do when I turn the master switch on...

So I close the driver door, arm the system. All the interior lights go out after whatever time frame Honda set it to turn off automatically. Then after a random amount of time (sometimes a few minutes, sometimes more) the interior lights would turn on itself and the alarm goes off!!!!! AH HA!!!! what the hell is causing the lights to go on??? no one is opening the door, the locks are not unlocking, no one is pressing on a keyfob... SO I am thinking in my head there is a short in one of the door switches!!! Since my hood and hatch switches are already disconnected... I turn off the alarm and open the doors one at a time and play with the door switches, and see if they turn the lights off normally. They all feel fine and look fine, but the front drivers, passenger switches when pressed one at a time (while the other doors are closed) only "dim" the lights a bit. So to me that means there is still and open door switch somewhere (grounded light wire/door switch) because if two doors switches are open and one is shut the other still keeps the light on. I suspect it is the rear right sliding door, it is the door I use the most for dropping the kids off, picking up the mother in law, closest to the curb side, etc... so I go and press on the switch on the left sliding door and the same thing happens with both the front doors, nothing but dims all the interior lights a bit.

Moving on the the right sliding door, I press on the switch and I can see that it has a different effect on all the interior lights, it makes the lights flicker and if I play with it and press really hard, the interior lights go out!!!!!!! All doors switches are closed!!!! WOW!! could this be it??? let me take that door switch off the frame and see if that can eliminate the problem. Done 10mm socket and the switch is in my hand in less that 30 seconds.

Closed the doors, arm the alarm sit in my car and start to put my stuff away, feeling victorious!!! with the defective switch in my hand, and the FREAKING INTERIOR LIGHT GO ON ITSELF!!!!! THE ALARM STARTS TO GO OFF!!!!!!! WTF!!!!! I had enough for the night, it's 10pm and I know where my children are, in bed!!! I'm in the New York City area, It's April 4th and the temp outside is a cold freakin 32 degrees!!! It should be in the 50's at night now!!! I am freezing, I am beat, I had enough with this for the night... Disconnected the Negative cable from the battery, told myself to call it a night. Went in got a beer, started to look online for any other insights and here I am rambling on.... I am sorry to all that finds this rambling useless and not helping you in any way. I am just venting and maybe what I have done so far may help someone out, or at least give them some ideals of what may be a problem. If anyone has some other ideals of what to do please post them!!!!

Sorry again for the rambling!!!!

PS I think in the AM, I am going to disconnect all four of my door switches and see what happens with all of them off.... If that does not work, then I am at a lost. something is ground out somewhere, maybe the interior light control module where ever that is. The ignition switch, since it also sends a signal to the turn the lights off when the car is started... anyone what to chime in????

 

Also another wire connector more towards the bottom closer to the "latch hook" I disconnected that one and the rear interior light now is off, and the idiot light for the rear hatch is off on the dash. BTW that micro switch was not held in place with much, other than two plastic plugs and they both broke off so I twisted the switch out

How do I remove the 'micro switch' properly? Any instructions somewhere on this so it can be reinstalled later? Thanks for sharing your experience.

 

So as an update to my last post. I have disconnected all my door (four of them), hood, and hatch/tail gate switches and for the past 72 hours. I personally have not had my alarm go off.

So my conclusion for this mess is that one or more of my door switch(s) were acting up. Instead of hunting to find the defective switch or switches. I decided to just replace them with stock, factory, OEM switches at 22 bucks a pop. I know I can get them online for around 6 bucks. I did not want to deal with this alarm again!!! So I hope the OEM ones are of superior quality, and the quality assurance and tolerance to spec are so small that this will fix the problem. I will install them tonight all update in the near furture...

fingers crossed!!!!

 

Did this fix your situation?

 

I have an 2007 with 85k. Second owner. The rear latch seems to need to be slammed in order to get it to catch. Alarm started going off at times when I lock it and go into work or the store. Really annoying when it happens in the garage.

Anyway - Can you post links to what switches/latches you replaced, especially on the rear tailgate. I'm guessing my faulty switch is in the rear!!

THANKS!!

 

If you have to slam the rear tailgate to get it to latch you have more problems than just the switch for the alarm.

 

The latch is a little loose and I haven't had time to adjust it or get a new one. It shuts but just needs extra force. I'm guessing that this is where my fault is as the alarm goes off when I use the trunk, lock the car, and go inside somewhere. Would love to see links as to what marky69 actually purchased for the rear tailgate

 

I got in a little fender bender about a month ago in my 2013 Hyundai Veloster my alarm kept going off. I was told to change the fob battery and it still kept going off soo I knew it had to be from the accident. I looked up on YouTube and the man took out the front hood censor and I did that and it hasn’t gone off but I’m wondering if that can effect anything else in the car? Please help

 

I’ve contributed to many random alarm threads on this forum over the past 10 years but have not seen this one before.
Although disconnecting the hood switch sometimes solves the problem, it is not always caused by a bad hood switch.
Instead do this to disable the alarm system: disconnect the wire harness connector to the hood switch and then install a thin jumper wire into the disconnected female half of the connector. This will fool the alarm system into thinking the hood is always open and prevent the alarm system from arming itself. No more random alarms. Of course, this is a bandaid trick and does not solve the root cause of what causes the alarm to go off. Usually water intrusion by the way.

 

My information is correct to find the cause of unwanted alarms.

If the hood switch is disconnected and the alarms stop, the hood switch or its adjustment is the problem. If the alarms continue, the problem is somewhere else.

You are also correct - to jumper the hood switch connector disables the alarm system.

It depends on the goal: to find the problem, or to bury it.

 

My information is correct to find the cause of unwanted alarms.

If the hood switch is disconnected and the alarms stop, the hood switch or its adjustment is the problem. If the alarms continue, the problem is somewhere else.

You are also correct - to jumper the hood switch connector disables the alarm system.

It depends on the goal: to find the problem, or to bury it.

What you say here is correct. Sometimes random alarms are caused by a faulty hood latch switch. But what you posted in #4 indicated that jumpering the hood switch connector would cause the alarm to go off. In fact it disables the alarm because the system thinks the hood is open.

 

Yeah, you're right, I was wrong on that point. (Edited the post to correct the error.)

One thing I like about the forums is others who take the time to correct erroneous information. The result is increased quality of the content.

Humble pie is bittersweet, though.

 

How do you know jumping the hood switch (mentioned here by thscott) will fool the system and disable your alarm?
Answer: the lights will not flash when you press the lock button on your fob, and the honk will not sound when you press the lock button twice. But your doors will lock.

But, why the heck the lights flash when I do the unlock button

 

Also, the blinking light on the dash does not blink, indicating the alarm system is not armed.

 

This thread helped me but was at first a little confusing. So here's a summary of what everyone has contributed for us dummies:

1. Disconnecting the plug to the hood latch switch indicates to the system that the hood is closed. If the hood latch switch was the problem then that fixes it, though leaving the hood unprotected.

2. Shorting out the plug (i.e., connecting the two wires together) indicates to the system that the hood is open. This prevents the alarm from arming because it won't arm if any door is open. So this fixes the problem even if the problem is somewhere else (e.g., another door or rear hatch). But it also leaves the vehicle unprotected.

In my case the peace and quiet was much more valuable than the protection of the alarm!

 

Excellent summary! Thank you. Welcome to this forum!

 

I just started to have a similar issue just today. Came back from work, got in..kids were playing outside. Wife comes in, and told me the Ody alarm went off?...I was like...nahh..(I was vacuuming so, couldn't hear a thing)...again about 30mins later while the kids are doing homework the alarm goes off ... I'm thinking is someone else, went outside and the Ody alarm is beeping...turn it off with the FOB. Try to lock it up twice...and the horn doesn't go off. I try unlock - then lock twice horn doesn't beep. Red light confirming that the alarm is armed, is not coming on.

After researching here, I disconnected the hood latch, try unlocking/locking using the key lock and still the alarm doesn't get armed (no beep after locking twice and no red light on the gauge). The only way I can armed the alarm even hear the beep is while being inside the car doors unlocked I turn the ignition to the ACC position then back to LOCK, I remove the key, press lock on the fob twice...doors locked, horn beep and red light comes on....weird thing is that the windows switches light stays on....will try to make a video soon.

 

Again, did these issues develop during or after rain?

Did anyone have these issues with an always "dry" / garage kept van?

Water infiltration is a possible cause. Any other odd electrical issues?

Ever heard of the roof rail seam leakage issue?

JMT

 

I had a similar situation a few years back in the Middle of the night the alarm went off, but the alarm kept arming without issues. I did the roof seams and everything was fine, two leaks were fixed. Rear trunk and passenger side kick panel. I have checked the kick panel area en everything looks dry. I took the car to the cars wash on Saturday, but compared to the storms we usually have down here...it is nothing. I'll have to take a look at the wires again behind the passenger area. Car is always outside.

 

Update: didn't do anything, yesterday morning was having the same issue, I drove to work and after parking I pressed that bad boy twice and beep beep...we are back in business. Anyways I will take a look at the passenger kick panel wires for any wet spots.

 

Oh my gosh! @marky69, that was the funniest post I’ve read in awhile. Anyhoo, I recently acquired a 2004 Odyssey EX and I’m working through some gremlins. One was a busted junction switch on the right sliding door. None of the locks lock or unlock with the fob or the drivers door switch except the lift gate and it only locks or unlocks with the drivers door switch. Odd, but no alarm issues.

So, I ordered a new junction switch and installed it yesterday. Door locks still don’t work right but today my alarm went off for no apparent reason. I went out and unlocked the drivers door and came in to research the issue. Found a thread that discussed disconnecting the hood switch. I did that. Shut everything and locked the door and went back inside. Two hours later, my alarm is going off again.
I’ll jumper the connector to the hood switch in the morning but to get back to the junction switch. What a strange design that is with plungers and stationary targets.

The terminal “I” was broken out. That’s the feed from the passenger multiplex through the unlock side of the door switch to ground through pin “K”. I’m suspecting that door lock actuator has failed and fixing the junction switch now triggers the alarm randomly for some unknown so far reason. I know the hood switch wire jumper is temporary but I need to be able to lock this van without disturbing everyone everywhere. For now the van is unlocked.

 

Hi everyone. Bottom line up front, a fuse box replacement is what finally fixed our random alarm problem. We got a new front hood latch and back door latch out of the 4 month troubleshooting process though . Got the fuse box cheap from an auto salvage yard and had the dealer install for under $150. Hope this helps someone out there.

 

Schrect, which fuse box? On mine, the box by the driver's foot was wet.

 

Passenger for me...

 

Both the driver and passenger side fuse boxes are used by the security system; both have multiplexers; both multiplexers are also used.

It's easy to see how water in either one could cause unusual security system issues.

 

Did everyone see @marky69 posts?

Post # 6, 7, & 9.

Solution could be simple door switches / plungers.
Fascinating.

 

Can I just pull out fuses for alarm or horn? Where is fuse location for alarm?

 

Ok, thanks for that, I'm a newbie.

 

Hello, i am having the same problem with my 2008 odyssey, the alarm goes off randomly at night. I disconnected the hood sensor and it seemed to work but now the alarm is going off again. Would you have any pictures or video to jumper the hood switch because i am really not familiar with cars... thanks for your help!

 

jumper the hood switch

Easy.

Get a paper clip. Break off one leg so it's left with a U shape. Insert each leg of the U into a cavity of the hood connector. If you have it, add a wrap of electrical tape to give additional strength to keep the jumper in place.

Keep in mind that the hood switch is just the most common cause of random alarms. Any of the door switches could also cause random alarms.

If you continue to have random alarms after jumping the hood switch, add a layer or two of electrical tape to the door jamb opposite each door switch. The tape will make sure the door switch remains fully depressed when the door is closed.