I'm installing a LC1 wideband, gauge, and HPTuner EIO setup in my car. I studied the schematics in the manual and it says that the ECU is connected to ground G102, which is located near the battery. The front cigar adaptor also goes to this location. Originally I was just going to ground everything to the ground on the cigar plug, but I have my doubts if the wiring could handle the current load from the heater grounds. So I am thinking I will put a lug on a 10ga wire and connect to ground G102. From here I will run it through the firewall to a distribution block like the picture below. And then I am just going to hook all of the grounds to the other end of the block.
Does anyone know what sort of current the heater wires pull? Would it be ok to use the cigar lighter for everything or am I correct to put in the extra work running the wire? Its a 2005 GTO BTW