FM-870 in 93 GMC Sierra, neutral safety

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=58222
Printed Date: May 09, 2025 at 10:55 AM

Topic: FM-870 in 93 GMC Sierra, neutral safety

Posted By: jasonw611
Subject: FM-870 in 93 GMC Sierra, neutral safety
Date Posted: June 22, 2005 at 6:43 PM

I am installing a Commando FM-870 in a 93 GMC Sierra 4-WD K-2500. I can’t seem to find the vehicle’s neutral safety switch or wiring. Could some please tell me what color wire to look for and where is the best spot to connect to it?

https://www.commandocaralarms.com/itemdetails.asp?Productid=496

I am also wondering whether I should use a normally closed or normally open starter kill circuit? The FM-870 has an output for each mode.

https://www.the12volt.com/relays/page2.asp

https://www.the12volt.com/installbay/forum_posts.asp?tid=29696&KW=gmc+sierra+

Thanks For The Help

Jason

Replies:

Posted By: mo12v
Date Posted: June 22, 2005 at 7:26 PM

Switch should be down toward the floor on Steering Column

Neutral Safety

ORANGE / BLACK (-)

AT SWITCH ON STEERING COLUMN **

** If Equipped With Electronic Automatic Transmission, Neutral Safety Switch May Be Mounted But Not Wired. Two Bare Terminals Will Be Present. Ground One Terminal And Take Neutral Safety Wire From Remote Start To Other.

-------------
MO

Don't Learn from Others Mistakes
You Might Be the One That Knows.

Posted By: jasonw611
Date Posted: June 23, 2005 at 12:17 AM

Thanks for the quick reply...

Posted By: infoaudio01
Date Posted: June 23, 2005 at 12:52 AM

Normally closed starter kill will allow you to disconnect power to the alarm brain and still start your car. Normally open starter kill will not start if there is no power supplied to the brain. i.e. better security, but if your brain becomes defective then you can not start your car without reconnecting the starter wires. Hince, shops tend to wire starter kills normally closed, because if a customer has a problem wth the alarm and connot start the car, all the customer would need to do is disconnect the brain via fuse or harness.