02 f-150 seatbelt switch starter interrup

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=70689
Printed Date: October 12, 2025 at 8:37 AM

Topic: 02 f-150 seatbelt switch starter interrup

Posted By: p&gcustoms
Subject: 02 f-150 seatbelt switch starter interrup
Date Posted: January 13, 2006 at 4:12 PM

i got a ford 02 f-50 and i'm trying to put a starter interrupter I'm using the passive starter kill w/remote turn on lead and i have it wired to the seat belt when u push the button down it gives me a positive and when u let it go i get nothing so i when ahead and wired it but it doesnt seem to be switching the relay i checked the voltage 11.3 that's enough to switch the relay but nothing any suggestions on how to get it to work

Replies:

Posted By: p&gcustoms
Date Posted: January 13, 2006 at 5:13 PM

anyone

Posted By: p&gcustoms
Date Posted: January 13, 2006 at 5:14 PM

bump

Posted By: p&gcustoms
Date Posted: January 14, 2006 at 12:59 AM

i used the passive starter kill w/remote turn on lead technique but it doesn't seem to be giving enough power to switch the relays i have the seat belt wire connected to where a cd player amp or whatever should be connected i replaced it for the seat belt switch but nothing and like i said i test the power out put from the seat belt switch and it gives me 11.2v or 11.3v and when i hook it up to the relay i get an odd reading of 1.230v or something around their i tested the relays with straight current from the 12v power outlet and they click and switch i also reved the engine and got the seat belt switch to give me 13.4v that should be enough to switch the relays. thanks

Posted By: KPierson
Date Posted: January 14, 2006 at 3:35 AM

Well, your seat belt input is probably driving in input on a control module. The input is probably sinking your 12vdc, and is most likely capable of roughly 25mA. A relay draws roughly 80mA - 120mA.

I would definaly unhook the relay before you cause permanent damage to the control module.

Many new cars have computers that are consistantly monitoring low current inputs such as this. The monitoring computer only cares about the (-) side of the switch, but the computer will rest at a (+) voltage (through a pull up resistor) to provide a threshold voltage for the digital input.

If you want to use this signal you will most likely have to put in a driver circuit, consisting of a tranisistor in a few other other components.

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Kevin Pierson

Posted By: p&gcustoms
Date Posted: January 14, 2006 at 11:00 AM

thanks