Fog lamp wire coding

[Mike A]

Might anyone have an original factory installation to document the wire coding. My schematic shows only a “fog lamp relay connection “, a connector wherein the solid white low beam wire coming from the DIP switch is distributed to the headlamps. (I’ve changed all that with relays to get the headlamps power out of the dash switches).       I’ll be adding a fog relay and circuit protection but would like to use what the factory may have used for both the front and rear fog lamps. Thanks for any replies, Mike 

Edited August 4, 2020 by Mike A

[Conserv]

Hi, Mike,

 

There's not much in the way of factory prep wiring, perhaps nothing for a round taillight. My tii is in storage in PA, however, and I can't even double-check or photograph what is there. I have only photos of the car that already happen to be in iPhoto!

 

Square taillights have relay triggers for both driving and fog lights. Fog lights can only be used with low beams and driving lights can only be used with high beams, if you utilize the triggers. I use both on my '76.

 

Round taillights have only a trigger for one set of auxiliary lights. Most people believe it is for fog lights, and thus is powered solely when low beams come on. But few people use it, and I have this odd recollection that it is just the opposite: a trigger that is only powered when high beams are utilized. If I'm wrong, that's fine because more people install fog lights than driving lights. But check before you complete your car's auxiliary lighting wiring.

 

The attached photo shows the plug, just above the front of the battery in the '73, with a new white wire coming from it. The plug appears to have been hit with the Malaga bomb that obviously exploded in the vicinity of the car, ca. 1983. I believe that white wire heads to a relay for driving lights -- but I can't check, now!

 

So that's my total sum knowledge. I'd just check that open plug -- yours should be open unless it's had auxiliary lights installed previously -- for power, on low beams and high beams.

 

Best regards,

 

Steve

 

 

 

 

 

 

[Mike Self]

Way back when (about 1969/70) in my youthful ignorance WRT pre-existing fog or driving light wiring on my 2002, I made up my own, and it's very simple.  You have a roundie tii, so it would be wired the same way as my '69 or my '73.  

 

Fog lights:  mount your relay next to the horn relay, the round can between the brake fluid reservoir and the voltage regulator.  Look closely and you'll see a pre-drilled hole there--that's meant for a fog light relay; for authenticity you can use another horn relay if you can find one.  Regardless, get a 4 terminal relay (the 4th terminal is the ground).  Mount a switch on your dash or console-your choice of locations, and run a wire from the parking light terminal on the headlight switch to one terminal on your fog light switch, and run another wire from the other fog light switch terminal to the trigger terminal on the relay.  By wiring it that way, your fog lights will go on only with the parking lights/tail lights--and more importantly go off with 'em, so you won't accidentally leave them on and run your battery down.  Having fog lights go on with your low beams kinda defeats the purpose of fog lights.  To supply power to the lamps themselves, either run a heavy wire (10-12 gauge) to one of the 15 amp fuses in your fuse box-- fuse 9, 10 or 12, or run a wire with an in-line fuse directly to the 6mm bolt on the + battery terminal.  Then run another heavy wire from the load terminal on the relay to the fog lights.  Finally, run a short ground wire from the ground terminal on the relay to a convenient ground--the relay's mounting screw, or one holding the brake fluid bottle.  Now you have fog lights that, when you push/pull/flick its switch, will go on (and off) with the parking lights, low beams or high beams.  

 

If you're interested in doing driving lights, PM me as this post is getting too long.  The trigger wire goes to a different source, and there are a couple of tricks you can do with driving light wiring. 

 

mike

 

PS--all German relays have the same terminal coding:  87 is the load terminal (your fog lights); 85 is the ground; 30/51 is the power source (fuse box or battery); 86 goes to the switch.  

[Mike A]

Thanks Mike. Yes. Wiring is not a problem. Was only trying to determine what color wire would be used by the factory 

[Mike A]

13 hours ago, Conserv said:

Hi, Mike,

 

There's not much in the way of factory prep wiring, perhaps nothing for a round taillight. My tii is in storage in PA, however, and I can't even double-check or photograph what is there. I have only photos of the car that already happen to be in iPhoto!

 

Square taillights have relay triggers for both driving and fog lights. Fog lights can only be used with low beams and driving lights can only be used with high beams, if you utilize the triggers. I use both on my '76.

 

Round taillights have only a trigger for one set of auxiliary lights. Most people believe it is for fog lights, and thus is powered solely when low beams come on. But few people use it, and I have this odd recollection that it is just the opposite: a trigger that is only powered when high beams are utilized. If I'm wrong, that's fine because more people install fog lights than driving lights. But check before you complete your car's auxiliary lighting wiring.

 

The attached photo shows the plug, just above the front of the battery in the '73, with a new white wire coming from it. The plug appears to have been hit with the Malaga bomb that obviously exploded in the vicinity of the car, ca. 1983. I believe that white wire heads to a relay for driving lights -- but I can't check, now!

 

So that's my total sum knowledge. I'd just check that open plug -- yours should be open unless it's had auxiliary lights installed previously -- for power, on low beams and high beams.

 

Best regards,

 

Steve

 

 

 

 

 

 

Steve That white wire confirms what my schematic shows and calls it a “fog light connector “. And it’s the low beam signal for whatever add on relay presumably would have been used. Unless someone chimes in with more info , I suspect that indeed it was for fog lamps. Memory is vague but autobon driving was especially hazardous and often saw those little bright red lights below the rear bumpers on all sorts of cars. As for fog lamp wire colors I ll wing it 

Edited August 5, 2020 by Mike A