do i need a relay?

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=102907
Printed Date: May 13, 2024 at 5:10 PM

Topic: do i need a relay?

Posted By: rfwave
Subject: do i need a relay?
Date Posted: March 09, 2008 at 1:20 AM

remote starter ( Autostart AS-1755 ) installing in to 2000 Pontiac Grand Am . the first time work on this , im not sure if i need to wire a relay for the doorlocks or not ?

Thank you .

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Replies:

Posted By: luckytii7
Date Posted: March 09, 2008 at 1:58 AM

Heres a link to the diagram for the locks

https://64.85.6.129/extrainfo/diagrams/15941_GRAND-AM_GRAND%20AM%201%20WIRE%20JBS%20UNITS.pdf

Is this your first remote start?

You have to remove the radio but dont disconnect it to get to the ignition wires. this makes a tight area to solder in so take your time. other than that this car is pretty straight forward except the bypass for passlock 2 and that depends on what bypass you use

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Posted By: chadwa2003
Date Posted: March 09, 2008 at 8:26 AM

The most correct way to do one wire door locks is to use relays some people don't just preference you can also go directly to the door lock relays in the car on the drivers side of the dash and tap in there you can also get your trunk release there. When you remove the panel it will tell you what is what for all the relays

Posted By: tedmond
Date Posted: March 09, 2008 at 11:36 AM

i would use 2 relays. that is the most correct way and you dont risk damaging anything.

Posted By: chriswallace187
Date Posted: March 09, 2008 at 1:13 PM

Theoretically, and according to every wiring info sheet I've read, you need a relay for both lock and unlock.

In practice, since the lock doesn't go through a resistor on the white wire you can PROBABLY get away with only using a relay and resistor for unlock.

The following detail is technical so feel free to skip it.

The reason for needing one relay is the way that the Body Control Module interprets the signal on that wire - if it sees a small current it thinks 'unlock' and if a large current it thinks 'lock'.

The switch in the car's door goes directly to ground; your alarm's (-) lock and unlock outputs go to ground through the transistors and other circuitry inside the alarm. What that means is that the current values from the alarm outputs through a resistor are significantly off from what the BCM considers a valid 'unlock' signal, and it won't do anything.

I've done several cars like this where the straight (-) output would work but the (-) thru resistor would not.

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Posted By: rfwave
Date Posted: March 17, 2008 at 12:40 AM

Thanks my friends !

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