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Performing an LS swap and have read that I have to bypass the VATS. I have already located the starter kill relay and connected the two heavy wires at the relay. See image below. Do I still have to also install a VATS bypass module? FYI, I am all wired and am getting no power when I turn the key (to crank or run) to any of the supposed "hot" wires. Thank you.
Looks like you have a third gen F body ? Also looks like you have bypassed the old vats starter cutout relay. Good. Does engine crank ?
How is your harness wired ? What was cut/removed ? You have to look at the stock power distribution system of the car that feeds the main firewall connector.
I dont think this is a pcm programming issue from what you describe, altho that may still be a problem later.
Thank you. Yes, 3rd gen F-body swapped with an LS1 & 4L60E. I have bypassed the neutral safety switch by using a relay that is connected directly to the starter solenoid "S" terminal and then to a "hot" ignition wire (10AWG Yellow wire?) when key is in start/crank position. Still not sure why getting no voltage to any of the ignition wires when turning key. Also using the OEM LS1 PCM and the wiring harness is from Painless part # 60508. Thank you in advance for any assistance!
Ok,
If your car had the F body VATS then its prob 89 or newer ? Was factory EFI orginally. TPI or TBI ?. How did you remove/adapt the existing EFI harness ? From the factory the 3rd gen EFI harness spans the whole engine compartment and taps into the starter battery lug to feed all the power distribution that goes to the dash, ign switch, lighting systems etc.
Some guys yank/cut this original harness and end up in a similar position as you are now.
If you arent getting any power where you expect, key on, I'd start by tracking down the original thick red wires that went from the starter battery lug to the C100 bulkhead connector plug near the brake booster. Do you have wires there on the starter now ? Do the lights work ? Does the fuel pump prime ?
The 3rd gen F body vats system was fairly simple and you have bypassed its starter cut relay so should be OK.
@gjetico: yes, 1991 TBI. Regarding the old harness, see y post #4 above. "Also using the OEM LS1 PCM and the wiring harness is from Painless part # 60508." As for the thick red wire," also see my post #4 above where "I have bypassed the neutral safety switch by using a relay that is connected directly to the starter solenoid "S" terminal and then to a "hot" ignition wire (10AWG Yellow wire?) when key is in start/crank position." I get no power at all (i.e.: lights, fuel pump, nada!). Thank you!
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VATS (pass key) Bypass 
