headlight relay

Can I run just one relay on the power to the low/high switch instead of two after it?

 

Thats what i did on my home made wiring job, the only problem i would see is it might loose some voltage going through the switch. I dont think there is any problem with doing it that way though

 

I have my dimmer relay powering a 30/40 amp relay (power switches from one leg to the other when activated, not on/off like the simple fog light relays) to switch between high and low beams. Gives me full voltage to the headlights since no power goes through the old crusty dimmer switch. Works great!

 

I guess the answer to that depends on how many amps your lights are drawing. Running one relay before the dimmer still puts all that wattage through the dimmer switch which will likely shorten the life span of the switch contacts even if the switch is rated for the amperage you are using. It also somewhat defeats the reason for using relays to start with. Separate high and low beam relays after the dimmer switch remains the best way to wire the headlights-the high wattage draw only passing through the relays.