DIY-Independent Fogs with highs as well

[banndit]

Good in theory, but they wired these cars a little strange as far as lighting goes. Are you familiar with how a relay works? Its basically an electrically controlled switch. Well, the button on the dash supplies a ground to the coil of the relay (the part that actuates the switch) to control the fog lights.

The ground wire on the button only has a ground to give the relay IF the headlight switch is pulled all the way out. It isn't as easy as splicing into the parking light wire as the parking lights are positive side switched. You would be tapping into a plus where you need a minus.

The other problem is the positive side of the coil.... It's connected directly to where the low beam headlights get their power from, if there not on, theres no positive to the coil. That part is all in the fuse box.

Oh, they changed all of this for late model cars, more stuff is powered from different stuff in the fuse box.

And scotch locks still suck, overheating corroding pieces of junk.

this is great info. When did they change the wiring from the fog light switch proving a ground to the fog light switch powering the relay?

B

[DaveSmed]

I'm *always* willing to learn something, so if I'm wrong, great!, but follow my logic here. The parking lights always have power at the headlight switch. The low beams don't have power unless the key is on. Same with the high beams (via the headlight switch and relays).

Logic would then say that if you wanted the driving lights to have power any time the parking lights are on (parking lights, low beam, or high beam) that the "easiest way" would be to tap the output from the headlight switch to the parking lights and run it to the input to the fog light switch. You would want to cut the current input to the foglight switch to prevent feedbadk to the other lights. Scotch loks are ok in a dry environment, but you could solder/ heatshrink to be more electrically sound.

B

Good in theory, but they wired these cars a little strange as far as lighting goes. Are you familiar with how a relay works? Its basically an electrically controlled switch. Well, the button on the dash supplies a ground to the coil of the relay (the part that actuates the switch) to control the fog lights.

The ground wire on the button only has a ground to give the relay IF the headlight switch is pulled all the way out. It isn't as easy as splicing into the parking light wire as the parking lights are positive side switched. You would be tapping into a plus where you need a minus.

The other problem is the positive side of the coil.... It's connected directly to where the low beam headlights get their power from, if there not on, theres no positive to the coil. That part is all in the fuse box.

Oh, they changed all of this for late model cars, more stuff is powered from different stuff in the fuse box.

And scotch locks still suck, overheating corroding pieces of junk.

[banndit]

Scotch locks are the work of satan for one, and two, soldering to a circuit board that has other connections soldered to it to have the current flow and circuitry match what would be the OEM way of doing it (if the car was set up that way factory) is much cleaner.


Besides, that doesn't solve the fact the relay simply doesn't get power unless the headlights are on. Gotta get the power to it, gotta be in that fuse box.

I'm *always* willing to learn something, so if I'm wrong, great!, but follow my logic here. The parking lights always have power at the headlight switch. The low beams don't have power unless the key is on. Same with the high beams (via the headlight switch and relays).

Logic would then say that if you wanted the driving lights to have power any time the parking lights are on (parking lights, low beam, or high beam) that the "easiest way" would be to tap the output from the headlight switch to the parking lights and run it to the input to the fog light switch. You would want to cut the current input to the foglight switch to prevent feedbadk to the other lights. Scotch loks are ok in a dry environment, but you could solder/ heatshrink to be more electrically sound.

B

[DaveSmed]

oh, I dunno, so you can use two scotch loks and about 3" of wire instead of drilling holes in circuit boards and or relays in a not really foolproof way in a non-waterproof environment?

:shrug:

B

Scotch locks are the work of satan for one, and two, soldering to a circuit board that has other connections soldered to it to have the current flow and circuitry match what would be the OEM way of doing it (if the car was set up that way factory) is much cleaner.


Besides, that doesn't solve the fact the relay simply doesn't get power unless the headlights are on. Gotta get the power to it, gotta be in that fuse box.

[banndit]

why?....

oh, I dunno, so you can use two scotch loks and about 3" of wire instead of drilling holes in circuit boards and or relays in a not really foolproof way in a non-waterproof environment?

:shrug:

B

[franco90]

can't you just run the power wire to the fog light switch from the parking light feed at the headlight switch? Its a low power circuit and it would power the fog lights anytime the parking lights are on.

B

why?....

[banndit]

can't you just run the power wire to the fog light switch from the parking light feed at the headlight switch? Its a low power circuit and it would power the fog lights anytime the parking lights are on.

B

[bignate948]

i have been wanting to do this for a long time and i have some time this weekend so i think that ill try this.

[So Live]

i was about to say you guys are pretty G-code till i saw spinning tires's post. thanks for putting up a more "correct" way to do it.

all this wrapping wires around relay posts to other relays lolz

While your in the fuse box, you should get the high beam and fog light indicators (in the dash board) to dim with the rest of the lights. that would be tits



...Looks like i have a project for saturday :) tomoro will be reading the diagrams

[Schnell_e30]

I have to say, this was one of the easiest mod's I've done on my e30! Thankyou for the information Spinning Tires!! For anyone who is wondering about this, dont be intimidated its really simple.

take out the one relay and take out the three screws


then break the connection on the circuit board with a screw driver or a utility knife. solder a wire to the spot right next to the break you just made. in my case i used a grey wire. this connection is located directly opposite the side where the relay was removed to get the screw out in step one



Last, connect it to the parking light wire which runs through the inside of the fuse box. you can use a test light for this or just see what color wire is going into your parking light.

[SchnellerVert]

Euro cars have a funky three prong adapter that goes in the blank area.

[juscool]

So which is the easy way ? I'm ready to rewire my lights.

[Mr Deagle]

you guys are doing this the extremely hard way

[87-325ic]

i dont understand where the grey wire originaly gets soldered to, could you better describe this please?

i had sealed beams originally, rewired for smileys, and jumped two relays (pin 30 and 30 from high and low beam relays), all 3 can be on, but i cant get my fogs to come on with just the parking lights on..

[Spinning Tires]

if you do it the way i pictured it would work. from the factory the fogs are run off the low beam circuit. this keeps them from coming on with the highs and parking. the way i did it hooks it up to the parking light circuit. and since all your doing is turning on a relay which requires very little power to do. you dont have to worry about popping any fuses