Anybody Know How To Disable a Car Alarm?

Superman · 08-16-2012, 08:01 PM

My sister's old, decrepit Honda Civic was parked behind my house (she's borrowing my truck). It has/had an alarm system that has been mostly disabled, but a light on the dash flashes. Today, I noticed somebody had been in the car (nothing of value was there) and the car's electrical system is not working. Battery is perhaps dead, but I don't know that.

What do lowlifes do to disable a car's electrical system? What happened?

KevinP73 · 08-16-2012, 08:07 PM

Factory alarm or aftermarket? If aftermarket, what kind is it? Most aftermarket alarms can be disabled by removing the main fuse. Some will have a starter disable relay that you'll have to remove or bypass.

RWebb · RWebb's Garage

there is a product called 45 ACP that works well

cstreit · cstreit's Garage

Quote:

Originally Posted by RWebb

there is a product called 45 ACP that works well

Haha!

crustychief · crustychief's Garage

An old trick was to drill a hole in the bottom of the battery the day before you went to "collect" the car or its contents.

lm6y · 08-17-2012, 01:21 PM

Also, most install shops just looking to earn a quick buck don't fuse the parking light wire. Bust out a parking light, short the contacts together with something metal, and it fries the alarm module, or pops the module's fuse.

Racerbvd · Racerbvd's Garage

Geronimo '74 · 08-18-2012, 11:42 PM

^^^lol

Superman · 08-19-2012, 09:47 AM

Update: I have time to look at the Civic. The battery is/was DEAD. Zero voltage. It is on the charger now and seems to be accepting a charge. When the perp went through the car, I suppose it is possible they left the door open or something and then, perhaps, a neighbor shut the door out of kindness. The door was closed when I found it. Anyway......before I plug this battery back into the car, I wonder if there is a way I can first verify that there is not a MASSIVE draw somewhere. I checked the resistance of the electrical system by hooking an Ohmmeter at the two battery terminals. It sees 1.1 Ohms of resistance. There is a flashing alarm light on the dash and perhaps other systems that use electricity even when the key is off, so I'm not sure this resistance test tells me anything. How can I check to see whether there is a potentially cable-frying electrical short in this car before I hook up the battery?

RWebb · RWebb's Garage

I'm poaching that pic Byron.

Superman · 08-19-2012, 10:41 AM

I think I know the answer to my question. I first hook it up using a fairly heavy wire with an inline fuse. Right?

genrex · 08-19-2012, 11:50 AM

Sorry, Supe, I don't know electrical. Obviously you know your way around batteries, the safety do's and don'ts. Since the car is an old Honda as you said, then maybe the battery is old? Is the date of manufacture still visible on the top? It's possible that she drives the car on a daily basis, but letting it sit for too long was enough for the battery to die. I hope it still takes a charge.

_

crustychief · crustychief's Garage

Take a headlight and hook it inline with the battery cable. if your headlight comes on bright there is a current draw, if it is dim then you have a very low draw. Kind of like a redneck ammeter.

Zeke · 08-19-2012, 12:04 PM

To measure the draw, disconnect the ground wire and put your meter in line with the cable and the negative terminal. Use DC Amps as the test setting. Start at the highest setting and switch down until you get a reading. If the needle pegs at the highest setting (unlikely), immediately disconnect the meter. If you put a multi meter across the terminals + to -, you will most likely fry the thing.

nynor · 08-19-2012, 03:28 PM

Superman · 08-19-2012, 05:01 PM

Quote:

Originally Posted by crustychief

Take a headlight and hook it inline with the battery cable. if your headlight comes on bright there is a current draw, if it is dim then you have a very low draw. Kind of like a redneck ammeter.

Interesting. Thanks. Makes sense, and I do have a spare headlight handy.

I don't have an ammeter, Zeke. Wish I did.

Zeke · 08-19-2012, 06:22 PM

Quote:

Originally Posted by Superman

I don't have an ammeter, Zeke. Wish I did.

OK. If there is a draw, it will light a bulb. You won't get a headlight to burn with mili-amps but you could light up a small bulb like from a flashlight. They use 1.5 v, but with a low current, it would be OK to put one in line as I described. Key off, of course.

If that sucker lights up bright or burns out, you have a significant enough current to use up a battery over time.