I'm install front fog lights on my Volvo 240, and I've got everything in place, but the switch. I should arrive sometime next week. But in the mean time, I'd like to have everything wired up and back in place, so when the switch shows up, I can just plug it in and be on my way. My question is, what exactly do I need for the switch?

I already have:
12V coming into the switch
12V leaving the switch and going up front to the relay
Ground for the illuminated portion of the switch to show it's on

Are there any other wires needed on the backside of the switch?

Thanks!

 

Do you have the lead for the illumination switch? I wired mine from the relay itself, from 87a I believe. Of course, you could just use the hot wire from the fuse box after it goes through the switch to illuminate the light so you don't have to run an extra wire through the firewall. I just did it that way so I know if the relay has an issue. Doing it the easy way illuminates the light no matter if the relay is on fire or not.

 

I figured the switch would just pick up the 12V for illumination from the 12V coming in to be switched, but I guess not. So I need another 12V+ for the switch to light up? I would if I could just use a jumper from the 12V+ coming into the switch? My + for the switch hooks into fuse 13 at the fuse block, which is for heated seats that I don't have.

 

Unless the fog light switch is designed like the A/C or rear defroster switch(which an OEM one is not), you will need another lead.
Those switches have the light lead incorporated into the switch like you think.

If you lead directly from the fuse box, the light will always be on. You need to lead from the wire that is going to the relay(from the switch).