I want to test out my cathodes, but i have no car how can i test them out? i ordered them from SVC and i want to know what they will look like

 

They should run on any 12V source, you should be able to connect +/- to any car battery.

 

On the subject of cathodes, can they plug into the factory wiring harness? Got an RS1 and the 'neons' are pure crap. Just curious as to whether they are compatible with the stock wiring setup. TIA

 

don't think they can b/c the rs1 lights don;t have a plug and inverter. you could just tap into the wires that it already uses and use the switch also. thats what i have done
the back window lights are the only ones you can see but they use the illumination switch. check out my ride https://www.scionlife.com/forums/viewtopic.php?t=15827