Window lifters/Immobiliser problem

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=58409
Printed Date: May 13, 2025 at 5:04 AM

Topic: Window lifters/Immobiliser problem

Posted By: chuckstasy
Subject: Window lifters/Immobiliser problem
Date Posted: June 26, 2005 at 8:13 PM

Hi,

I've recently bought a set of window lifters, and it seems that it will only work with a positive trigger. The immobiliser output of my alarm (Steelmate 888 2-way) sends out a negative output. I've solved this problem by connecting a relay as follows:

pin 30: +12v

87: trigger wire to window lifters

85: +12v

86: negative when armed on (alarm)

It seemed to solve the problem, and the windows closed perfectly. The new problem that arose is that the car no longer immobilises and I can now start the engine while the car is armed! How is this relay affecting my immobiliser circuit?

Any help would be greatly appreciated. Thanks!

Replies:

Posted By: Powermyster
Date Posted: June 27, 2005 at 4:09 AM

yep use a diode

Posted By: chuckstasy
Date Posted: June 27, 2005 at 6:40 AM

Ok...thanks, I'll give that a try!

Posted By: chuckstasy
Date Posted: June 27, 2005 at 8:47 PM

I've had a go at it...installed the diode, and the window lifters are working fine but the immobiliser still doesnt work!

I've had a closer look at it, and when the system is armed with the window lifters connected, the "negative on arm" wire goes from 12v to 0v immediately after arming, then back to 12v within about 5 seconds.

When I disconnect the relay for the window lifters, I get a negative output, and it stays negative, and the immobiliser does its job fine.

Can someone explain where this 12v is coming from??? From what i know, the relay coil should have around 80ohms across it, and should take up the entire 12v, so there shouldnt any 12v at all!!!

Posted By: nava94
Date Posted: June 27, 2005 at 11:16 PM

you have to use two diodes one to isolate the starter relay and the other to isolate the lifter relay.make sure the band stripe on the diodes face the alarm brain and your problem should be solved.good luck.