I am in the process of changing my car over from a manual to an automatic. In the manual the car uses the switch on the firewall connected to a heavy purple and a heavy yellow wire around 10 gauge or so. The switch on the side of the auto shifter doesnt appear up to the task of whatever amps are pushing thru this 10 or so gauge wire.
Are appearances decieving? Do automatic cars also run 10 gauge wire thru the little switch or do I need to set up some sort of a relay system?
Thanks
Roy

 

Yes they are. Think of the current the flows through the tiny element in a fuse. Also, the neutral switch only has to carry the load untill the car is started. In my buds truck, since we don't have a shifter for it yet, I just use a 4" 20ga jumper wire across the harness plug to start it.