Ignition Wires

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=8998
Printed Date: September 11, 2025 at 12:46 PM

Topic: Ignition Wires

Posted By: Devil_Boy
Subject: Ignition Wires
Date Posted: February 03, 2003 at 11:34 AM

Hey,

On my alarm i have a yellow wire that is suppose to connect to a ignition wire that has 12v as soon as the car is on even during cranking, but drops to 0v as soon as the car shuts off. I have this wire hooked up to the ign wire (the one after you start your car your keys falls back on) but it does not work and troubleshoioting says ts the wrong wire. So should this wire be hooked to the ACC wire instead????

Thanks Jeff

Replies:

Posted By: PLAYER69
Date Posted: February 03, 2003 at 11:45 AM

What vehicle is this? Year, make and model.

Posted By: Devil_Boy
Date Posted: February 03, 2003 at 11:56 AM

it is a 85 mazda 626

Posted By: PLAYER69
Date Posted: February 03, 2003 at 12:05 PM

So you should have it hooked up to a BLACK/ white wire?

Posted By: Devil_Boy
Date Posted: February 03, 2003 at 12:19 PM

Yes i do.

i have to wires going to the IGN wire one from my starter disable relay and one from the alarm that says "12v ignition wire: Connect the yellow wire on the main harness to a main ignition wire. This can be found in the main ignition switch wire harness. Your volt/ohn meter will read 12v when the key is turned on.
Make sure that this ignition wire has 12v+ on even during the starting process of the vehicle. It is important that the voltage does not drop wen the car is started. Some vehicles have ignition wires that remain or slowly drop to 0V. Verify that when the ignition is shut off that the voltage drops to 0V immediately.

Hope you can help i guess ill go start testing wires.

Posted By: ViperATC5
Date Posted: February 03, 2003 at 12:48 PM

the ignition wire should drop to 0 volts as soon as the car shuts off as you have indicated in what you wrote earlier. The only problem would be if the ignition wire was dropping voltage while the car was running. It seems that you have the ignition wire correctly identified - perhahps the problem is elsewhere in the install - what are the problems that you are experiencing?

Posted By: Devil_Boy
Date Posted: February 03, 2003 at 1:16 PM

ok i got the good ol' volt meter out and it does read 12 volts like it said...... (And the valet switch works)

the problem i am expirencing now is that the car does not seem to want to arm i open the hood and the hood pin goes up whoch grounds (like it should) my led comes on solid to show that one of the alarm triggers are open the car will then arm with the hood open and 30 seconds later chirp to say it bypassed that trigger cause its open. As soon as i shut the hood, nothing i hit the button on the remote and it dont work. nothing happends.
When the car is armed witht he hood open the shock sensor works.

my alarm has both wires for negative and positive door pins. I have negative door pins (when the door is opened it grounds the interior lights and such; Which is negative right?) i have used both wires and nothing works though??

So please help.
Thanks again Jeff

Posted By: Devil_Boy
Date Posted: February 03, 2003 at 1:18 PM

The alarm is a commando 501-s
https://www.commandoalarms.com/501install.htm

Posted By: Devil_Boy
Date Posted: February 03, 2003 at 2:03 PM

WELL here was the problem. i sat there thinking about the wiring and how it was weird that the alarm would only wirk when the hood pin was up (giving it a good ground) so after a bit i went out there a bingo the ground of the hole damn alarm was pulled off of where i had it grounded to. i grounded it good now it works like a charm.
So for all those beginners like me. Check your wiring. Bercause that one simple wire gave me hours of frustration...

Thanks to all of you who helped me in my many posts, and the quick responses.
THANKS, Jeff