Joined: Apr 2006
Location: On the road n NE Oklahoma
The relay kits are a good idea for ANY type of light. Some lights have to have them, such as headlights with more current draw than the stock wiring was designed for. But most can benefit from a headlight circuit relay installation because most cars have part, or all, of their original wiring.. current passes poorly thru this old wiring due to increases resistance. The HL relay kit solves ALL that, plus it keeps the main current out of the HL switch, another source of issues when they get old, or when some aftermarket lights are installed requiring more wattage to pass thru the switch.
PS. this is why your lights are brighter when a relay kit is installed, i.e. More current is getting to the bulb itself instead of being absorbed by the wiring of high resistance.
'65 K code Mustang
& a few '66 GT350's (1970-2012)
Last edited by zray; 10-11-2017 at 11:27 AM.