Hazzards activated some time last night and ran battery down

[broncosteven]

Anyone else experience waking up to your car hazards flashing which ran the battery down? When my wife 1st noticed it I tried the hazard button but it didn't do anything. I then tried to turn the car over and got nothing, no clicking just silence. When I did that the external hazards stopped flashing so I thought it stopped and tried to get another hour of sleep. When I came back out I noticed the flasher button was still flashing and the lights in the car were flashing with the door open.

The battery is 10 years old but the light was green on it just a couple weeks ago. I did have a retired mech do an oil change last week but it drove home fine and worked a few days after that. I checked the hood sensor switch but it seemed ok.

I was looking around at other sites and some point me to a crash alarm relay but I can't find a good youtube of where it is and how to change it. The best I could find was a guy who said it was under the seat and was an air bag sensor which I don't want to mess with. Someone else said it was a brown relay under the driver side dash.

I am not a mechanic but am OK with replacing a relay or fuse as long as I know the air bags won't go off.

Figured when the wife got home I would jump it and check the battery and if it still keeps flashing I would disconnect the battery so it won't run it down again. Plus that way I check to see if the battery is holding it's charge.

If it is the Alarm or crash sensor I won't be able to drive it will I?

Thanks to anyone who can point me in the right direction, not a lot out there about this.

[randy72877]

I can help you with this. I am in west chicago just a few miles from you if you still live in Bartlett. I am a master tech with the equipment to diagnose every system in your car. Let me know if you want me to look at it.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[MIKYZZ4]

First item on the agenda?,
Replace that battery! NO jumpstart, unless you enjoy alternator replacement!

[broncosteven]

I can help you with this. I am in west chicago just a few miles from you if you still live in Bartlett. I am a master tech with the equipment to diagnose every system in your car. Let me know if you want me to look at it.

Sent from my SAMSUNG-SM-G870A using Tapatalk

How much would you charge to look at it?

[randy72877]

How much would you charge to look at it?

$50 but I won't charge you anything if I can't find the problem. I would also recommend replacing the 10 year old battery. Use the larger h8 size. It is a direct swap with no modification.

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[broncosteven]

$50 but I won't charge you anything if I can't find the problem. I would also recommend replacing the 10 year old battery. Use the larger h8 size. It is a direct swap with no modification.

Sent from my SAMSUNG-SM-G870A using Tapatalk

I have something to do Thursday. I thought I would buy a bosch battery Friday and see what happens after leaving the old one disconnected for awhile. Would you be able to come out the week after Christmas?

[MarcoZandrini]

Do you have a Walmart nearby? They sell batteries at good prices. Btw, there are 3 lead/acid battery manufacturers in the US. A Bosch battery is likely made by one of those manufacturers. Just get a Walmart battery.

[RobertDenali]

I didn't read the whole thread but get a new battery and if this continues buy a new hazard switch.

[MIKYZZ4]

I didn't read the whole thread but get a new battery and if this continues buy a new hazard switch.

Sounds sensible.

[Raddee]

I actually think the hazard lights are a consequence of the battery being bad rather than the cause. If the battery runs low, stuff starts acting up and the alarm may activate, causing the hazard lights to flash. Just replace the battery first; it's old anyway.

[MarcoZandrini]

Whacky voltages cause whacky issues.

[shogun]

on some models there was a problem with defects in the crash alarm relay https://www.bimmerforums.com/forum/s...sh+alarm+relay
known problems in E36 E34 E32 E31 Z3

[randy72877]

E46 does not have that relay. The hazard lights are activated by the lcm in the event of an alarm trigger by signal sent over the k-bus from the alarm. Airbag module sends a crash signal over the k-bus that causes the lcm to activate the hazards and the general module to unlock all doors.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[broncosteven]

So it turned out to be the hazard switch. I bought a new hazard switch and a new battery (Auto zone H8-AGM Platinum), popped the battery in and the hazards came back on, I went into the car and hit the new hazard switch and they turned off.

I was hoping that was all it was because when I pulled the old one out I tried to clean it off and swabbed pepsi out of the inside of the connection to the cable. I haven't spilled anything in there, at least that I know of, for a long time but I guess it finally made it deep enough to the contacts to short it out. I knew I needed a new battery eventually but was hoping to wait another month or 2. Then after reading the other posts and realizing that I was going into the heart of winter I decided to go with a new one. When I bought this car brand new I told myself I wanted to get at least 250k out of it. Nearly 17 years and 140k later she is still on the road.

Many thanks to Randy for his tips and offering of help. I might need you down the road. It is always good to have options and a 2nd pair of eyes.

Hope this helps someone else down the road. I also noticed a lot of other threads with the same problem dying after the mention of a new hazard switch.