Hella FF50 Installation

[SWB]

As I've admitted before, I know just enough about wiring to be dangerous. I wired a set of tractor lights on my RT-P when I first got it, using the "Euro" three-position light switch (as on/off only) and a hot lead from under the radio box to activate the lights. The hot lead ran through the harness (e.g. ignition switch cut power to the lights). I wired the two-wire hot/ground lead with hot to the switch, hot exiting the switch and split to the two lights, and return/ground on both lights merged back to the ground lead.

 

I decided to upgrade to Hella FF50's on brackets by EMP Designs. I vaguely understand switches (e.g. single wire grounded to the handlebars, or double wire grounded to the harness or to the bike elsewhere). From reading on this site, I realized that (a) using the lead off the harness I have less than 12/14V power to that light, and (b) a light drawing more amps (like the FF50's) could overload the switch or the harness, or both. I also know that a relay is itself a switch, and that a relay is required so that all power does not run through the switch or harness.

 

To install the FF50's, I'm running a hot lead from the RT-P (second battery) directly to the fused Hella relay, and using the Euro switch to activate the lights. It would be nice to be able to use the bright switch to activate the lights with the OEM "brights" (using the Euro switch to power off the Hella's while using the OEM brights alone). However, I'm too "gutless" to cut into the BMW light harness to hook the "green" (dashed line) lead (see attached image) from the BMW "brights" to the relay. Problem is that the relay doesn't seem to activate without that green wire. Can someone explain how to wire the FF50's from hot-lead to the relay to the lights, using the two-wire Euro switch to activate it, without using the green "bright" lead? See attached image for context (I believe "II" is the proper implementation for my bike).

 

Thanks,

 

Scott

[SWB]

Well, after reading through some of the posts, I want to set up the lights "the right way".

 

• I'm going to try to figure out which OEM "brights" wire should be connected to the green relay wire (i.e. Relay activation wire).
  
• I want to use the three position European lighting switch to set the lights to "off", "on", and "off/on per brights/autoswitch".
  
• I may try to use the diodes installed for the RTP emergency lights to indicate that the FF50's and fog lights are activated, if I can figure out that procedure (seems like I just need to insert the diode in the hot lead).
  
• Going to install the relay (actually relays; writing a Stebel horn as well) into the battery compartment, and wire both off a hot lead connected to the RT-P battery positive pole.
  

 

Any advice or help would be appreciated. Doesn't seem to be a very difficult procedure, but I don't quite "see" the big picture.

[Ken H.]

To get the Euro switch do what (I think) you are wanting, you're going to have to cut into it's harness. It's just not designed to control auxiliary lights (like your FF50s) as is. The good news is it can be done. Here is the diagram. If this isn't what your wanting it to do, let me know and I might be able to modify the diagram.

 

 

I'm not following what you are asking about a diode. Are you talking about some type of indicating lamp, or an LED?

[SWB]

To get the Euro switch do what (I think) you are wanting, you're going to have to cut into it's harness. It's just not designed to control auxiliary lights (like your FF50s) as is. The good news is it can be done. Here is the diagram. If this isn't what your wanting it to do, let me know and I might be able to modify the diagram.

 

 

I'm not following what you are asking about a diode. Are you talking about some type of indicating lamp, or an LED?

 

This looks good. Let me digest it and I'll get back to you. Yes, I mean a single LED light, but thought they called them diodes. I have two in my dash from the "Official days" which were used as strobe status lights. I figure I might as well put to use while I'm tearing into my wiring.

 

My euro switch harness has been cut on before; no big deal.

 

I understand +, -, and Gnd, but not "W/Y". Which goes back to the issue of where I pull power from the OEM brights/light harness.

 

Thanks,

 

Scott

[Ken H.]

I understand +, -, and Gnd, but not "W/Y".

White/Yellow. On BMW bikes the low beam lead is a white wire with a yellow stripe, and the high beam lead is a solid white wire.

 

For an LED 'lights on' indicator it can be connected across either the input or output of the relay (I'd use the output). Pins 87 & 85.

[AndyS]

.... a hot lead from...The hot lead... I wired the two-wire hot/ground lead with hot to the switch, hot exiting the switch..... It would be nice to be able to use the bright switch to activate the lights with the OEM "brights" ..without using the green "bright" lead?

Scott

May I if you mean a 'hot wire' to be something that always has a standing 12V on it or do you mean a switched 12V?

Also what do you mean by 'brights'?

Maybe something has been lost on me when I ran the bablefish american to english translator

Andy

[Francis]

I installed this set-up using a micro switch available from Cycle Gadgets. The lights are activated with the turn signal cancel switch. I had looked at the Euro Switch approach but it looked to complex to cut wires etc.

 

Francis

[Ken H.]

May I if you mean a 'hot wire' to be something that always has a standing 12V on it or do you mean a switched 12V?

Also what do you mean by 'brights'?

"Hot" is standing, always on, 12V.

 

"Brights" is the high beam, non-dipped, headlamp.

[SWB]

Ken,

 

I see the "mandatory" diode on the White "high beam" wire. I don't have this on my wiring diagram, but noted on another post regarding air horns that a diode acts as a one-way switch, protecting the harness against a power surge. Was that your intent, or did you add that in response to my discussion about an dashboard LED? Why would I need one on that lead and not the yellow/white?

 

I've got the wiring tested and am in the process of trimming some factory length leads down to the length I need, and wrapping up with zip ties. If the diode is necessary, I'll have to make a trip to the electronics store tomorrow. What kind of diode would I need?

 

Thanks .. Scott

[Ken H.]

Ken,

 

I see the "mandatory" diode on the White "high beam" wire. I don't have this on my wiring diagram, but noted on another post regarding air horns that a diode acts as a one-way switch, protecting the harness against a power surge. Was that your intent, or did you add that in response to my discussion about an dashboard LED? Why would I need one on that lead and not the yellow/white?

 

I've got the wiring tested and am in the process of trimming some factory length leads down to the length I need, and wrapping up with zip ties. If the diode is necessary, I'll have to make a trip to the electronics store tomorrow. What kind of diode would I need?

 

Thanks .. Scott

It certainly would not hurt to put a diode in the low beam 'pick up' lead also. In my actual more complex installation on my bike, I have one there.

 

But in this particular circuit the one in the hight beam white wire is required to keep the low beam from feeding back and turning on the high beam (or worse do damage) when the Euro switch is in the top most position. (Aux lights always on.) If it wasn't there the current path would be from the factory low beam on the W/Y wire to the top terminal of the Euro switch, through the switch, out the bottom terminal of the switch on the grey/blue wire, then to the factory white wire and to the high beam; turning it on when you don't want it on. But with the shown diode in place; that path is blocked.

 

ISFA what diode to use, it's not that critical, only the relay current flows though it. I think I've been using 1N4001 or something similar to that.

[Capt_Ron]

I installed this set-up using a micro switch available from Cycle Gadgets. The lights are activated with the turn signal cancel switch. I had looked at the Euro Switch approach but it looked to complex to cut wires etc.

 

Francis

I see the diagram in the post, but how does the microswitch and turn cancellation switch fit in to the picture to replace the Euro switch. This is the route I want to go, also.

 

Ron

[SWB]

Ken,

 

By the way, the wiring is done and it worked perfectly as designed. I learned a little in the process. I'm going to add a headlight modulator down the road, which is why I wanted the extra control over the Hella's. Most of the time I'll use the brights and Hella's together, but if I put a modulator on, the Hella's will be off when the bright's are flashing.

 

- Scott

[Ken H.]

Ken,

 

By the way, the wiring is done and it worked perfectly as designed. I learned a little in the process. I'm going to add a headlight modulator down the road, which is why I wanted the extra control over the Hella's. Most of the time I'll use the brights and Hella's together, but if I put a modulator on, the Hella's will be off when the bright's are flashing.

 

- Scott

Nice work!