Im thinking about installing some fog lights on my 1992 240. I think lights like this BMW Saab Volvo Fog Light Assembly - Bosch 0305402102 | FCP Euro would be alright in the style like this. imgur: the simple image sharer
What do you think? And how involved would wiring them be for my car?
Any input would be great!
Thanks

 

yeah, basically. you'd need to drill the bumpers, and get behind the metal bumper to secure the nut holding them on, its not hard to unbolt the bumpers ... I took the front bumper off our 240 once for some body work, I think it was just 4 nuts on each side attaching it to the shock mount post. I removed the under-bumper 'lip' first (and never put it back on, the silly curb scraper always annoyed me)

wiring is pretty straight forward... you'll need to install a on/off switch on the dashboard, and get a standard "Bosch relay" and a socket for it, along with a fuse holder and a 20A fuse...

• one side of the switch goes to ground, the other side of the switch to a control wire that you run up front under the hood somewhere.
• wire this control wire to pin 85 of the relay (coil ground side).
• wire pin 86 of the relay to a 'vampire tap' on one of your low beams 'hot' side. this way the relay only activates when A) the low beams are on (thats the law) and B) when the switch is on. now...
• run a power wire from the battery or the positive terminal through a 20 amp inline fuse to pin 30 of the relay.
• wire pin 87 of the relay to the hot side of both fog lamps.
• run the other side of both fog lamps to ground.

I'd install the relay somewhere up front, near where the fog lights are going. it should be in a protected space, like where the existing headlight relay is. the battery -> relay -> fog lamps -> ground wire should be heavy gauge as 2 55W fogs is 110 watts, which is nearly 10 amps.. the other control wires don't have to be heavy at all, they aren't carrying any current.

 

Alright, where would I go about getting the relay? I searched for relays on FCP Euro and there are a bunch of them. Not sure which is needed... For a switch, would the one for the rear fog light work, or should i get another one.

 

bog stock 4 pin generic Bosch relay, any local auto parts store should have them.

you don't normally want your front fog lamps on the same switch. I know the 740/940 optional factory fog lamps are on a seperate switch. I'd probably just find a suitable switch and cut it into one of the blank panels.

ooh, i just found a mistake in my wiring above, I fixed it (the fog lamps are wired to pin 87, not 86.).

the standard bosch relay has the coil between 85 and 86, and the switch common is pin 30, switch normally open is pin 87, and a 5 pin relay will have 87a for normally closed (not used here).

if your switch has a indicator light in it, then you'd wire the control circuit a little differently. basically, headlight to switch to relay coil to ground, and the switch's light circuit to the coil side of the switch and to ground, so the light is ON when the switch is closed.

something like this...


edit; in case its not obvious... that switch is wired such that the switch itself is between the center and bottom pin as drawn, and the indicator light is between the center and top pin. this way the light is on when the relay is powered... and by hooking the bottom pin up to the low beams, your fog lamps can only come on when the low beams are lit. you can probably tap the low beam signal behind the dashboard.... Its the green wire to pin 6 on the bulb failure sensor module (the failure sensor module is a cylindrical thing the size of a redbull can thats tucked up on the far left under the dashboard). the 3 amp fuse shown in that diagram on the switch wire is to prevent a short in your wiring to the switch and your relay from frying the headlight circuit.

 

oh, this relay is as good as any.
Audi VW Fog Light Relay - Bosch 0332014134 | FCP Euro

 

Awesome! Seems fairly straight forward... When I get the money (may be a while) I'd definitely look into getting fog lights... Just out of curiosity, do white fog lights or yellow work better? I don't see how white fogs would really be any different than an extra headlight... Other than being obnoxiously bright when the weather doesn't call for them...

 

fog lamps should have a very sharp cutoff and be low and wide. very little light should escape above this cutoff.

the obnoxious ones are 'driving lights', which are only supposed to be used with high-beams, but many people install in place of fog lamps. also misadjusted fogs...

the problem with the fogs hanging under the bumper, they are pertty easy to bump and knock out of alignment. My plan for my 745T is to install projector fogs, Hella MicroDE to be specific, behind the air dam, so they just peek out through holes cut for this purpose. this is a photoshop of what they might look like.



and this is a closeup of one of the MicroDE's that I installed on my motorcycle about 7 years ago...



these lights may be small, but they put out a VERY good foglamp pattern, and use the same H3 55W bulb as the rectangulars you linked...

 

Those are nice lamps! I looked them up on Google Images too to see what they put out... quite nice indeed! They're a little pricey, but maybe eventually... They also look like they'd take a little less to get them attached to the car, for example, less cutting of the bumper pieces to do so.

 

Susquehanna MotorSports - High Performance Vehicle Lighting and Competition Accessories is where I get Hella stuff. good folks, good service.

those DE's have been on my bike now for like 7 years and 100K miles and are holding up just fine. the lenses are some kind of really thick strong glass, quite resistant to sandblasting, the bodies are metal alloy. they do get very hot when they are on, so they should be mounted so they aren't touching any plastic..