I hooked up my carputer to the lock and unlock triggers in the body control module via a 4 SPDT relay assembly so it would turn on when I unlocked my doors with the keyfob and off when I press the lock button. This way the computer is just about done booting by the time I start up the car.

The following diagram should explain how everything is connected. If you are having trouble reading the relay circuit diagram, check out the relay section at http://www.the12volt.com. You can purchase the 4 relays needed to construct the circuit at http://www.allelectronics.com/cgi-bi...421&type=store




219079-g35 alarm turn on computer.JPG

 

I must be a newbie because I can't figure out the upside or the downside to this functionality. Please elaborate

-Chris

 

It means I can turn on the custom carputer I mounted in my car (https://g35driver.com/forums/showfla...view=&sb=&vc=1) on and off outside of my car with just the keyfob. This means that I can cut ~10s or so off the boot time that it takes me to get in my car and start it after I unlock it. It also means that I have greater control over the starting and stopping of the computer since it is tied to the lock and unlock not just to starting and turning off the iginition of the car.

I can now start my carputer from inside my house, then as soon as I get it the car, it is fully booted and ready for use.

 

Nice module...how is your computer powered??

 

OPUS 150watt power supply check out the link to the other thread I posted earlier for more info on the carputer.

 

god_of_cpu-

I thought your computer was powered by an OPUS 150w psu connected to the car's ignition switch. Does you unlock/lock circuit trigger an ignition signal?

-except10n

 

Very interesting design. However, it can be done with two relays based on the fact that the G uses a reverse polarity acutator and that both the 'lock' and 'unlock' wires rest at ground when you arn't locking or unlocking the doors. You way works also, but it can be hard to install and make 4 relays look good under the dash! (DEI remote start satelite harness comes to mind!) As always, I have never tested the circuit posted here, but, in theory should work!



Kevin
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04 Diamond Graphite Coupe - FULLY loaded
Windows up with OEM Remote

219947-MotorLatch2.GIF

 

Yes, the relays trigger the iginition signal on the OPUS.

Kevin, wish I had your circuit last week looks much simpler, soldering all the wires for the 4 relays was annoying, but it was the only way that I could think of doing it at the time from what I interpreted from the service manual. There's actually ample room for the 4 automotive relays I used right under the BCM though so its all good.

 

Certainly....

It doesn't!

Sorry, my mistake, I got the ground terminals on each relay backwards (pin 86). The Lock wire rests at ground until you lock the doors, then it switches to 12 volts and takes the ground away from the relay, thus breaking the latch.

Also, you should place a diode across the coil of the first relay (the one on the left) so that when the coil's magnetic field colapses it doesn't backfeed 12vdc back into the BCM of the car!!!!

This is how it should look:


Kevin
----------------------------------------------------------------
04 Diamond Graphite Coupe - FULLY loaded
Windows up with OEM Remote

220604-MotorLatch2.GIF

 

Yeah its amazing what accurate information will do! I've been working on a slightly different way to do this, but I hit some snags, maybe I will finish it this weekend.


Kevin
----------------------------------------------------------------
04 Diamond Graphite Coupe - FULLY loaded
Windows up with OEM Remote

 

Nice job on the carputer install.

I have a question about the opus 150w. Are you wiring the
12v+ directly to the battery and also the 12v switched are you connecting it to the ignition wire.

 

Man i sure would like some help with doing this with just the 2 relays. So then will i be able to start the carputer with the disarm, and shutdown with arm?

Can anyone tell me in lame terms how to do this. I know my wires for my dei alarm, just dont know what wires i should choose to put the relays at.

Thanks.

 

The 2 relay circuit should be hooked up to the exact same lines as the original 4 relay one.

Just connect the wire that says Lock in the 2 relay wire diagram to the line on your alarm that gets a momentary pulse when the lock button is pressed on your alarm and unlock to the one that gets a pulse when unlock is pressed. If you can't figure out which lines on your alarm are pulsed from the wiring diagram, just hook up the negative trigger line of a single relay to ground and then go through each wire on your alarm and hook it up, one at a time to the positive end of the relay, then press the unlock or lock button on your keyfob, if the relay is triggered (you should be able to see or at least hear it click momentarily) its the right line.