Jc803

iTrader: (2)

Posting here because I'm sure some other LS drag racers have done this already.

I have an aluminum steering column which has no key switch and put everything on a switch panel. To do that I had to wire in a resistor to the VATS crap in the BCM and now have a push button start and switches for power to everything. But I want to get rid of the BCM completely and remove the wires from everything I dont use or removed (which is a lot)

I'm just confused as to how to do this. If you have to wire in a resistor to bypass VATS to start the car, I would imagine the car wouldnt start at all if you unplug the BCM. If I remember right the BCM stops the car from starting I think, so I'm guessing the starter would have to be wire differently.

But I dont know if thats the only way the BCM keeps the car from running and I'm sure I'm completely wrong about everything because I'm the worst when I comes to electrical stuff.

RENE'S RAGE

iTrader: (96)

If I remember right, you'll have to send a hot to your fuel pump relay from a toggle switch or by a ignition hot. And ground your start relay, and put the hot for the start relay on a push button.

Jc803

iTrader: (2)

Sounds easy enough. I think the only thing on the BCM I want to keep is power windows so I'll re wire those too. Thanks

RENE'S RAGE

iTrader: (96)

I'll check tonite about the relays, but I think I'm right, been a long time since I did mine.
Yeah, the windows are all you want to keep, I got a wiring diagram on them too.

transampetews6

iTrader: (31)

As far as I know the BCM controls windows, locks, key fobs and security. If you eliminate the key switch all you need is the right value resistor to make everything work. I can't see it weighing that muck to keep?

Jc803

iTrader: (2)

I'm not removing it for weight. I'm getting rid of every single wire on the car I no longer use and doing a complete wire relocate and tuck to make it look cleaner under the hood, plus give me more room under the dash to put everything

Boosted SS

This I am also curious to know about, I am thinking about getting rid of the BCM and switching to a spaghetti menders setup. How are you guys still controlling the power windows. I don't care about power locks or anything just want my power windows to work still, since I will be driving it on the street any info on this would be great. Thanks

01ssreda4

iTrader: (96)

The resistor goes to BCM, if the BCM is happy it sends the ok signal to the PCM to tell it to crank, when the pcm gets the ok, it adds fuel. Simply disable the vats ok signal needed in the pcm (in the tune) and it wont matter whether the bcm sends it or not, computer will crank regardless. Yall are way overthinking this.

01ssreda4

iTrader: (96)

So what we've learned today is you cant resistor trick a bcm thats not in the car mmmk?

RENE'S RAGE

iTrader: (96)

The BCM does 2 things to get the car running. It grounds the start relay. Car will not turn over if there's no ground. It sends a hot to the fuel pump relay.
The reason to remove the BCM is to eliminate all the unwanted wires.

transampetews6

iTrader: (31)

Doesn't it also control door locks and receive key fob signal?

01ssreda4

iTrader: (96)

Yes it does to my knowledge.

RENE'S RAGE

iTrader: (96)

It controls most, if not all, electrical body components.
Once removed, you'll have to re wire what you want to keep.
No more key fob, no more security.
This mod is for race car only. All you need to re wire is fuel pump relay, start relay and windows.

Zmg00camaross

iTrader: (11)

Doesn't also run tail lights etc?

FirstGen F-Body

iTrader: (3)

anti theft, alarm, interior lights, DRL, coolant level indicator, door locks, starter enable, injector pulse enable, horn and seat belt switch. there might be something i forgot but i think thats it. On alot of stuff the bcm is piggy backing and can just be cut out and on some other things you have to splice a couple wires. fuel injector pulse has to be tuned out and you have to hook up a switch to ground the starter relay pin 86

RENE'S RAGE

iTrader: (96)

One of you, young cats, should google this, and get a diagram of the body computer circuits. I bet you could find one.

Jc803

iTrader: (2)

@01ssreda4, I think you're missing the point. I already have done the resistor trick and tuned VATS out. I already dont use a key fob, just old fashioned keys like people did back in the day. I have a switch panel that pretty much runs everything with no keys. I just want the BCM out and all the unused wires with it to make more room under the dash so I can remove the fuse boxes from under the hood and make a fuse and relay panel to put under the dash.

Like Rene's Rage said, this is pretty much a track car. If I wrote a book on everything I've removed from the car it would be thicker than the Lord of the Rings books.

Jc803

iTrader: (2)

@FirstGen F-body, what do you mean you have to tune out fuel injector pulse? This is the first I've heard of it. Sounds like a few people are saying to rewire the fuel pump to get fuel.

RENE'S RAGE

iTrader: (96)

You don't have to tune out the fuel injector pulse.
Just have to get a hot to your fuel pump relay. I put my fuel pump on a toggle switch, so I can turn it on when I want.

You also don't need a switch for the start ground wire, just ground it to the chassis.

Jc803

iTrader: (2)

Works for me. That answered my questions, thanks a bunch