MG CAR OWNERS FORUM

So far, I haven't been able to locate an existing thread that addresses my problem.
I have owned my 2001 Montero limited since it was new. Always got power outages. Five years ago, I misplaced the key fobs. It is possible to lock the vehicle and activate the alarm by using the key in the driver's door. Sure thing.
Unexpectedly, the garage alarm went off not long ago. No amount of keying in the door would be able to stop it. Got in my car, but the alarm wouldn't go off. It finally stopped after a number of attempts to lock and unlock.

But then the radio and screen would flash on for a second before going dark. After twelve occurrences, neither of them turned on again.
It seems like the moon roof is dead now. When you turn the key to the lock, it will lock and then unlock automatically; however, when you turn the key off, the lock will not lock at all. The windows open when the key is turned on, but they no longer briefly close and lock when the key is turned off, unlike before. Every time it is started, the trip odometer now resets to zero. In addition to causing idle issues, the computer's drive monitors clear every time it is started.

It was simultaneously that all these symptoms began. The system was functioning properly prior to the alarm going off.

So, what went down?

The battery connectors have been cleaned. Earth bolt connections from the crash bar to the body, points of ground in the engine bay and the dash center stack all lead to the earth. The same thing has happened.

I am currently perplexed by the security system module.

I need your assistance, please.

ps. The fact that it has served me well for the past quarter of a century is a testament to how much I adore my Gen3. Please help me find a solution to this.

Please share any wisdom you have with us.

The sudden emergence of all those electrical issues following the activation of your garage alarm must have been incredibly frustrating. Have you had an opportunity to check any particular fuses for the security system or interior electronics, now that you've cleaned all the main ground points? By providing those details, you may assist other users in identifying the problem with your Montero.

A built-in battery is a common component of alarm systems. If that fails, a plethora of strange electronic gremlins might appear.

Another option in contemporary automobiles is the vehicle's local area network (LAN). Another source of unpredictable problems could be a cabling system interface that is malfunctioning.

Much obliged for your replies.

I have verified every detail.

Since it is still drivable, I have continued to drive it even though this happened a few months ago.

I swapped out the heater core last week after removing the dashboard and crash bar. As part of that process, I checked for corrosion or burnt pins and disconnected the majority of the under-dash harness connectors. At that point, I was able to remove the crash bar's earth bolt grounds. The lack of clarity is disheartening.

I thought the LAN system was just an automotive version of Ethernet. Have you ever seen that on a car that's 25 years old?

There might be a security system battery.
Finding its location in the vehicle and giving it a try will be my next task.

That car has always belonged to the dry, sunny state of California. We uprooted our lives two years ago and settled in the humid, salty coast of Oregon. Uncertain as to whether that has had a negative impact.

Nothing is wrong, but every danger is illuminated in my Outlander. The repair shop did something that reset everything and couldn't find any problems. I turned off all the warning and error lights before I drove away. The alert lights came back on after ten minutes. Two years have passed, and I've been ignoring it ever since.