Safe way to relay fogs using relay

[vwtdi04]

I have question regards relay
On my VW I have relay my fogs in following pins on relay
Pin 86 to fog light switch
Pin 30 to fuse battery
Pin 85 to ground
Pin 87 to fogs

Friend of mine email that he wired as well and it works
Pin 30 to fog light switch
Pin 86 to fuse battery
Pin 85 to ground
Pin 87 to fogs

he had wire pin 30 to switch and pin 86 to battery he used the existing relay that was in his car, will this work or should I advise him to do like I have ?

 

[visionlogic]

You did it the correct way, your friend did not.

In an industry standard automotive relay: pins 85 and 86 control energizing the relay (i.e. the fog light switch), and pins 30 and 87 are the switched load (i.e. fog lights).

The way your friend has wired his the relay will be constantly energized by the battery and the fog light switch will just be running its output through the closed contacts of the relay. In other words, the fog light switch is carrying all the current going to the fog lights. And sooner or later your friend will end up with a dead battery due to the relay being always "on".

 

[vwtdi04]

thank you for information