[tprostock140]

I am to the point with my swap where i need to figure out the wiring to crank the new motor with the key switch. i'm just having a hard time finding the signal wire coming from the key switch. i have the yellow wire for the starter relay under the hood, just need the under dash wiring. Anyone familiar?

 

[GT Drew]

There is no wiring to change, if you replaced a V8 for a V8.

 

[tprostock140]

Im sorry, I am replacing a v6 with a v8. So the v6 ecm is removed, replaced with a truck v8 ecm. I have a stand alone wiring harness. Just need the key switch signal to crank it.

 

[95wagon]

Hopefully , someone will have the GM diagram but for now see attached.
The request from BCM goes to Engine ECM and it grounds the start relay.
does not appear to be an ignition switch type you can just " run a wire from "

 

[tprostock140]

Correct, im trying to see how others handle this circuit. Im sure someone has done it. The truck v8 ecm doesn't work this way.

 

[95wagon]

What truck ECM exactly and calibration?

 

[tprostock140]

It is a 2002 Chevy Silverado ECM I have not connected HP tuners to it yet so that's all I know.

 

[95wagon]

Numbers on ECM ?

 

[tprostock140]

I will get the number for you but not sure where your going. The ecm here is not envolved with cranking the engine

 

[95wagon]

411 it appears
I was trying to see if ANY applications - calibrations using your PCM could but no.
2005 E40 24x is earliest I see of this but no one in their right mind would convert to an E40.

Easy to say from the sidelines , a 58 reluctor, E38 and treat the whole deal as a GT would be my route.

I have no idea if the resistor in the switch for the start circuit is accessible.
If it was , possibly bridging it would allow you to run a relay control across circuit 1073 and 1390.
I'm bench racing at this point.
Good luck.

 

[Thawk]

What trans are you using with swap first ? As the Silv uses a straight 12v through ign sw start position while the G8 ign sw passes a voltage through a 300 ohm for request signal not a straight voltage to relay, so you may need to wire that yellow wire to a 12v push button switch through the park/neutral switch to start

 

[tprostock140]

4l60e

 

[Thawk]

At this point you can wire it as i posted with a push start sw to 12v to park/neutral sw to yellow relay wire or they sell modules that will engage by a very low volt input from G8 ign sw to low volt module to park sw then yellow wire

 

[Thawk]

PAC makes the low voltage triggers similar to this https://www.bestbuy.com/site/pac-lo...-black/9046098.p?skuId=9046098&ref=NS&loc=101

 

[tprostock140]

Any ideas on speedo and tach gauges other than after market?

 

[rockinlespaul]

I think you will find the answers you need on some of the G8 groups on Facebook. A few there have done the swap. Good luck.

 

[JCMG8]

Curious - how is abs managed? Ditch it?

 

[Thawk]

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