Fog light wiring: where to tap the trigger source?

[Dug Nichols]

I've found some great articles and posts on setting up a relay for adding foglights. I've got a vintage Hella 4RA 002566-11 relay and am looking for guidance on where I should tap into the trigger source that I'll connect to the 86 terminal on the relay. Research indicates I want to get it either from the solid yellow low beam wire going IN to the fusebox, or from one of the two (L or R) striped wires coming OUT of the fusebox. Which one is best?

 

Worth noting as that this particular relay has a fuse integrated into it.

 

 

[visionaut]

There’s pre-wired connections for fog lights.  See Steve’s post for details:

 

https://www.bmw2002faq.com/forums/topic/307487-mystery-items-in-engine-bay/?do=findComment&comment=1542935

[John76]

The tap on the left (above battery) is for the driving light relay (tab #86).

For fog lights, you can use the tap on the right (near coil) for the fog light relay (tab #86), or just run a shorter wire from the #9 fuse. The right tap (Grey/white wire) is in the front corner because it is commonly used for a headlight washer system.

Sketches for wiring driving lights and fog lights attached.

John

PS: Fog lights should only be powered when the LOW beam headlights are on. Driving lights only with HIGH beams.

 

 

 

[Dug Nichols]

I do have the tap above the battery but putting a test light on it (grounded to battery negative), and turning on the headlamps is not yielding signal. Tried with high beams just in case, nada.

So I thought I'd tap directly into the fusebox. I'm just not sure if I should tap BEFORE the fuse or AFTER. Before is the solid yellow, after is choosing either the Left or Right headlamp.

 

Also, my #9 fuse is the Heater Blower. I'd be tapping into either 3 or 4 (or the opposite side ahead of the fuse).

[Mike Self]

Many years ago I rigged up my driving lights to a double throw, double pole switch that gave me two options to use the lights (three if you count not using 'em at all).  

• The center terminal on the switch led to terminal 86 on my driving light relay.
• One end terminal led to the high beam terminal on the dimmer switch.  This allowed the driving lights to go on (and off) simultaneously with the high beams
• The other end terminal led to a fused power source, either switched via the ignition, or unswitched.  This allows you to use the driving lights by themselves--that can come in handy if you have a headlight failure.

For fog lights, I'd wire one of the switch's end terminals to the low beam terminal on the dimmer switch, and the other to the tail light/parking light terminal on the headlight switch. 

 

This will give you the choice of having your fog lights go on (and off) with your low beams, or allow you to use your fog lights independently of the headlights.  Wiring 'em through your parking/tail lights keeps you from forgetting to turn 'em off and run your battery down.  

 

mike

[John76]

7 hours ago, Dug Nichols said:

I'd be tapping into either 3 or 4

Doesn't matter since 3 & 4 are jumpered on the "hot" side.

My general rule: If you have 12V coming into the cabin (e.g., lighted switch for the relay tab #86), then tap into the fused side.

If you are switching the ground (relay tab #85) then either side of the fuse is O.K.. (Relay trigger only draws very small amps).

John

[Einspritz]

I like Mike's setup.

 

I have Ampilux with the low and high beams energized for high beams, Cibie Super Oscars for driving on Mountain roads, but tired of turning them on and off by reaching for the switch or oncoming traffic so I wired a "pre-switch" on the console by the shift lever then a small rocker IN the top of the shift knob in series independent of the headlights.

 

So, to energize, fip the rocker on the console and then when you need to operate the driving lights just click the rocker on the top of the shift lever.

 

If all the lights are on you can see the road kill before you hit it....... And it's halfway cooked by then!