DIY: Independent Fogs

[blaquea8]

This may have been covered before but I searched and couldn't find anything so here you go. I have been wanting to set my fogs up to work independently of the headlights and figured out a way to do so. There are several ways that the "other" e30 cars do this but none of those ways worked on my 89 M3 (production 9/88). So here you go:



1. Pull out the fog light relay (K8 in the first pic only mine was black...)
2. Solder a jumper wire between prong 85 and 30 (represented by the blue line) as close the the relay casing as possible.
***DON'T do it like the original pic shows (the little yellow wire with the big red "X" on it) - it didn't work...at least not on my car anyway***
3. Put the relay back into place and be sure it is full seated into the fuse box

That's it! Your fogs should now come on with just the parking light and will also stay on with you low AND high beams.

Note: I am not 100% that this same method will work with EVERY car but it worked for me. Do this at your own risk.

[chutrain]

I'll probably take care of this mod this winter. Now, I just need to find the reason why one of the foglights won't work. And yes, I did change the bulb! :focker:

[marques]

If you do this (jumping pins 30 and 85 in the fog light relay), what you'll have is a short circuit in the fuse box from the battery, thru the low beam relay, thru the fog light switch, thru the headlight switch, to ground, in an unfused circuit, whenever you turn on your headlights and fog light switch. In other words, not a very good idea. I would remove this jumper immediately if you value your wiring and car, as there is a very real possibility of melting insulation and even electrical fires.

If you want your fog lights to stay on with the high beams, all you need to do is jump pins 30 and 87a on the high beam relay. This is a low current signal, so the wire doesn't have to be big. Do not confuse pin 87 with 87a or you will permanently turn on your high beams thru the little jumper wire.

If you want the fog lights to turn on with the parking lights, you need to jump pins 30 and 87 on the low beam relay. This carries the full current of the fog lights, so size the jumper wire appropriately. You still need to at least turn on the parking lights for the fogs to come on, and this will not work with the very early cars which had a different headlight switch.

If you have one of the very early headlight switches, your best bet would be to upgrade the headlight switch and wiring to the later design.

-Luis

[blaquea8]

If you want your fog lights to stay on with the high beams, all you need to do is jump pins 30 and 87a on the high beam relay. This is a low current signal, so the wire doesn't have to be big. Do not confuse pin 87 with 87a or you will permanently turn on your high beams thru the little jumper wire.

If you want the fog lights to turn on with the parking lights, you need to jump pins 30 and 87 on the low beam relay.

That was what I tried originally, pins 30 and 87 on the low beam relay, and it made the low beams come on all the time....

Doing the 30/87 pin jumper would look like the original pic of the relay above with the yellow jumper wire (has the red "x" on it). That was what I tried first but like I said - it just made my low beams come on with the running lights and no fogs. I went back and was testing with my multimeter and the 30/85 jumper was the only way that I could get the results that I wanted which are mainly to have the fogs on w/just the running lights. I don't really care if they stay on with the highs or not.

[blaquea8]

So I tried this again and actually found that if I jumped 30/87a on the low beam relay then the fogs would come on with the running lights and stay on with the lows but turn off with the highs like normal. Anyone know of this being wire-melting solution like the 30/85 jump on the fog relay or is this just a working modification of the 30/87 suggestion?

[OnrailsM3]

So I tried this again and actually found that if I jumped 30/87a on the low beam relay then the fogs would come on with the running lights and stay on with the lows but turn off with the highs like normal. Anyone know of this being wire-melting solution like the 30/85 jump on the fog relay or is this just a working modification of the 30/87 suggestion?

Bump for answer to this question.

[jimmyC]

If you want your fog lights to stay on with the high beams, all you need to do is jump pins 30 and 87a on the high beam relay. This is a low current signal, so the wire doesn't have to be big. Do not confuse pin 87 with 87a or you will permanently turn on your high beams thru the little jumper wire.

If you want the fog lights to turn on with the parking lights, you need to jump pins 30 and 87 on the low beam relay. This carries the full current of the fog lights, so size the jumper wire appropriately. You still need to at least turn on the parking lights for the fogs to come on, and this will not work with the very early cars which had a different headlight switch.


-Luis

This should work , according to the wiring schematics I have. If jumpimg 30 to 87 on the low beam relay causes the low beams to come on as soon as you plug in the relay, try jumping 30 to 87b instead, Could be a misprint in the manual.

[Chucker]

So what's the solution to have independant fogs. please choose your answer carefully as no re-test will be given at end of grading period. Remember to choose the "most correct answer". Good Luck.

In order to have "independant Fogs" you shall/may perform the following.

a. Remove low beam relay and solder a jumper from 30 to 87?

b. Remove low beam relay and solder a jumper from 30 to 87a?

c. Remove low beam relay and solder a jumper from 30 to 87b?

d. Dont solder anything, put the car back together you risk a fire on your 19 year old m3 listening to these idiots?


chucker

[Jeremiah]

So what's the solution to have independant fogs. please choose your answer carefully as no re-test will be given at end of grading period. Remember to choose the "most correct answer". Good Luck.

In order to have "independant Fogs" you shall/may perform the following.

a. Remove low beam relay and solder a jumper from 30 to 87?

b. Remove low beam relay and solder a jumper from 30 to 87a?

c. Remove low beam relay and solder a jumper from 30 to 87b?

d. Dont solder anything, put the car back together you risk a fire on your 19 year old m3 listening to these idiots?

chucker

It depends on the year of the car. Also i'm assuming we're only talking about US spec cars here?

[Chucker]

That would be a 05/89 build date. a late year 1989 model. chucker

[marques]

a. Remove low beam relay and solder a jumper from 30 to 87?

b. Remove low beam relay and solder a jumper from 30 to 87a?

c. Remove low beam relay and solder a jumper from 30 to 87b?

d. Dont solder anything, put the car back together you risk a fire on your 19 year old m3 listening to these idiots?

chucker

Option "A" (according to the ETM) will allow the fog lights to turn on with the parking lights or low beams, but they will still turn off with the high beams. You might want to see if you can splice the wires inside the fuse box instead of soldering pins on the relay.

Obtion "B" is a trick question because the low beam relay doesn't have a pin 87a.

Option "C" will turn on the low beams permanently untill the battery runs down.

Option "D" is always a safe bet.

-Luis

[MTree]

What guage wire did you end up using as a jumper??

[Brewcity11]

I used 16 gauge, but use solid wire, not stranded.

[Chucker]

Here, Is what i did ON MY LOW BEAM RELAY!! and it didnt work.. I jumped 30 to 87.

Low beams came on immediately as soon as I plugged it in. Now what do i do?

jump 30 to 87b ? there is no 87a.

be shure we dont want to smoke test my 19 year old car.


chucker

[msjudged1]

Bring this back from the dead...

Has anyone found a solution to make this work on a '90?

I tried jumping relay 30 to 87 and my low beams came on when i re-connected the battery...

The low beam relay in my car does not have a 87a or 87b.

TIA.