head light relay

1. What amp rating is ideal for a headlight relay?

Ans - For each circuit, 20 amps is more than adequate; you can probably run a 10 or 15 amp fuse without any problems.

2. A headlight relay runs on what voltage?

Ans - The headlight power wire is used to feed the relay's coil, ensuring that it receives +12V electricity only when the headlight switch is turned on. The door switch will complete the coil circuit, which will complete the high current circuit to the warning buzzer, if the headlights are on and the driver's door is opened.

3. Why do you need a headlight relay?

Ans - That switch turns on a relay, which then turns on your headlights. The electrical link between your headlight lights and the battery is actually provided by that relay. Fuses are also used as a sacrificial failure point to safeguard the remaining wiring. 

4. Does a relay have to be used for headlights?

Ans - It has two benefits but is not strictly necessary. 1) The lights may be made brighter (full system voltage will reach the lights), and 2) The headlight switch will last almost indefinitely (because the contacts will only have to carry milliamps whenever the lights are switched on).