rogers2014

Hey Guys,

Ok so when i got my sc4 i only got the valet key with it, nothing else, my car also had a antenna issue so when i was fixing it, i realized there was no brain for the alarm! :O ok i said, but i'm going to be installing a alarm/starter (got a sick deal on it) would it make sence to wire the brain where the old one was? also in doing that would i be complicating the factory settings in any way? it seems like the easiest way to install the alarm/starter as the brain for the factory alarm is already gone lol

thanks guys,
Chris

MooJohn

That was my plan as well since most/all of the wires should already be at that location. I haven't gotten to installing an aftermarket alarm yet so I can't offer any practical advice on it yet.

rogers2014

Hey John thanks for the input, but i called lexus they said the brain is not near the antenna? can you help me confirm this? Also we will need a immobilizer apparently thats what lexus told me :S there pretty cheap on eBay but i do not think i"ll need one if the actual brain is gone lol

MooJohn

From what I've read you can't totally get rid of the alarm or the car won't start. First thing to do is keep the stock alarm from ever arming again by grounding its trunk ajar input. A quick google should find which wire that is.

You'll probably want to hijack the keyless entry module which is behind the side trim panel, passenger side, rear seat. You basically need power, switched, and ground plus the door sensors and this location will get you most of those. I'm hoping my 15 year old DEI alarm (barely used) will even be able to use the stock keyless antenna for longer range.

At least it's an easy place to reach and add whatever other wiring is necessary.