Yes you can use the stock switch. Look on your fuse block. There is a terminal there that stays hot in start AND run but I cannot remember what it is labeled. Use your Ohm meter and find that wire. You can come off the switch also, it's the same wire, just easier to access it at the fuse block.Hey Tom, guess who Quick question, how did you wire your ignition hot wires to your harness? I read this on lt1swap... The PCM also gets 12V+ from a KEY HOT source. This is what 'powers up' the PCM. Its important that this key hot power, along with power to injectors, coils, and so on, STAY HOT when cranking over the engine. Some accessory positions on key switches ARE NOT HOT when cranking. This also includes older vehicles that had POINTS ignition. Even the COIL wire on some of those went dead when cranking. This is because when cranking the coil was boosted to 12v+ through the R terminal on the starter solenoid. After cranking, power was restored to the coil through a resistor, lowering voltage to 6 volts.
Can I use my stock switch? Thanks again for being an amazing guy and a great resource!! Someday I will somehow repay you
The PCM needs a full time hot and the "switched" hot to work...