fog light relay?
Thread Starter
Member
Joined: Mar 2014
Posts: 147
Likes: 2
2002 CLK430
Basically I wanted a simple ignition on fog lights on (regardless of switch position or high beam)
So I pulled the fuse panel cover next to the headlight switch and got to work with the multimeter. Fuses 2 and 4 are powered when ignition is on. so I jumpered the line side of fuse 4 with the line side of fuse 9 (foglights). Bingo... fogs come on when ignition is in run position and off when it is off.
This was just a proof of consept and I don't plan on leaving it this way. I am going to install a relay on that line and power the fogs with a battery positive from the engine bay.
So I pulled the fuse panel cover next to the headlight switch and got to work with the multimeter. Fuses 2 and 4 are powered when ignition is on. so I jumpered the line side of fuse 4 with the line side of fuse 9 (foglights). Bingo... fogs come on when ignition is in run position and off when it is off.
This was just a proof of consept and I don't plan on leaving it this way. I am going to install a relay on that line and power the fogs with a battery positive from the engine bay.
Thread Starter
Member
Joined: Mar 2014
Posts: 147
Likes: 2
2002 CLK430
Well, the car doesn't have DRL's so why not use the fogs? I also hate that fog lights turn off with high beams. Don't know what moron came up with that rule... I realize I'll probably be replacing bulbs yearly, but the cost of an H1 bulb is uber cheap.
i also realized I don't need a relay for this. I moved my jumper on fuse #4 to the fused side of the circuit. That way the entire circuit is still protected for max 15A current. Doesn't blow the fuse even with all lights on.
piece of cake and down the road for a .03$ piece of 22 guage wire. Another note, don't use to small guage wire for this. I calculated DC voltage drop for 15A and came up with 24awg minimum.
i also realized I don't need a relay for this. I moved my jumper on fuse #4 to the fused side of the circuit. That way the entire circuit is still protected for max 15A current. Doesn't blow the fuse even with all lights on.
piece of cake and down the road for a .03$ piece of 22 guage wire. Another note, don't use to small guage wire for this. I calculated DC voltage drop for 15A and came up with 24awg minimum.
Last edited by miatawnt2b; Aug 8, 2014 at 10:21 AM.
