On my 1994 940 wagon I've been fixing all of my tail light problems (most just not making good contact), and I noticed on the driver side lamp there is an extra socket with a bulb and wires to it at the top of the assembly, above the reverse light. The passenger side however does not have this. The hole is blocked like it was a spot you could cut out if needed, but no wires going to that side I don't think. Any input on what this light is for would help. I cant figure out what signal gives it power either.
On another note, does anyone know where I can get the high mount brake light cover? I can't find any wagons at junkyards around here for some reason and the whole assembly is a bit pricey. When I got the car the plastic cover was missing so the silver reflector part hangs from the window by the wire.
Any help with this would be greatly appreciated.

 

that extra lamp is for the rear fog lamps they use in europe, only on the driver side. a 7/9 should have a dashboard switch for it. using those fogs in the US just confuses people as they aren't 'normal' here.

 

lol ok cool. Yeah I have a dash switch for foglights but don't have any up front. Would it be that switch or is that a switch for front fogs if I did have them?

 

if you had front fogs, that switch would have two positions, and two indicator lights.

my 1992 740 turbo wagon turned out to be wired for front fogs, so I got my hands on the dual fog switch, and the relay it requires, but havent done anything about installing fogs yet, after I discovered that switching from the rectangular plastic lights to the fogs requires replacing just about the whole front end of the car. Eventually, I'll probalby install some Hella MicroDE fogs under the bumper, inset into the air dam

photochop mockup:


shiny new microDE lamps I installed on my motorcycle 10 years ago (still going strong)



I like these fog lamps, they put out a excellent clean cut off fog light pattern, they are metal bodied, with thick glass lenses that take a beating from road crud and keep going. they use 55W "H3" bulbs. they are, however, a bit pricey.

 

I like those lights but yeah, not looking to spend a lot on my beater. I did want to install some sort of fog lights since the headlights are dim and I'm having trouble finding junkyard ones. I'll have to look at the switch wires, it's only a two position, on and off, then when I turn it on, the bulb out light pops up. I'm guessing it's only for the rear light but I might wire it up to some front fogs since I won't use the rear ever. Thanks for the info.

 

I replaced the yellowed rectangular plastic lights on my 1992 740 with "Depo" brand chinee copies, they are quite good, I've used Depo on several cars now (mercedes, volvo, toyota) with good results, they bolt right up, and have a good pattern, are virtually equivalent to bluebox (Volvo) OEM at a fraction of the price.

these lights start to yellow in about 10 years, the odds of finding a used set in any kind of useful shape is pretty slim.


if you do hook up foglights, use a relay thats triggered by the lowbeams.

wire like this...

ground -> dashboard switch -> relay coil -> low beam 'hot'
battery + -> fuse -> relay switch -> fog lamp -> ground.

I'd put the relay up near the front of the car so the fog lamp power travels the minimum distance.

do NOT confuse fog lamps with driving lamps. fog lamps have a sharp horizontal cut-off with a wide pattern, and are for use with your low beams. driving lights have a long throw round pattern, and are for use with your high beams only.