Adding fog lamps to my 16’ RG, when using the switch on the nacelle, is a flash needed for the BCM to know the lights are there and provide them power and/or turn off whn the brights are activated?

 

I'm unsure on that, but....

Did you add the switch or was it already there?

You could always check the switch with a voltmeter to see if it's "live" and passing 12V through the switch...

Good luck with the install..

 

Not sure about RG's, but for SG's no flash required.

I would think if the wiring is present, it should be plug & play. It will require a flash if you want them to be on with high beam, assuming you use left switch normally used with the aux lights on a Limited/Ultra.

If you use the center switch on the left side, you would have independent control irrespective of high/low beam switch. That option requires no flash either, but needs the accessories wiring harness.

 

I am not using the actual switch that Harley locates in the left switch pack location, because I don't have that location available, my nacelle has been completely removed. However, I have made a plug that will be plugged into the harness that plugs into the nacelles left switch pack location and would allow me to use a basic three prone on/off switch (I believe this is how the switch Harley uses also works). After going over the schematic and chasing the routing down between all the pages in the maintenance manual, I drew up my own schematic (below) using both the RG wiring and the RK switch. From what I can tell, the the V/BE wire coming from the P&A Relay has a constant 12v load that is provided by the BCM via the R/Y accessory wire. The V/BE wire goes to the switch (both the switch pack on the SG/RG and other fairing touring models, along with the switch on the nacelle of the RK). I did check the voltage on the wires a week or so ago and do believe the V/BE wire did in fact have 12v on it (maybe a little more). Also, based on the routing, it looks like the switch, when turned on, supplies a 12v load to the BE/GY wire that goes to the BMC ( I am hoping someone can confirm this and I can avoid the 90 min ride to a dealer to talk to a tech that probably don't know the answer), I would hate to send the load to the BCM if it would result in damage to the BCM. If I am correct, I suspect this either communicates to the BCM or passes thru the BCM to apply power to the BE/BK wire that goes to the turn signal connectors and on to the lights themselves. I can check the 12v thru out the system, just not sure about the load going from the switch to the BCM (the BE/GY wire).

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This doesn't answer your wiring question, but might be useful information. There is a flash to allow the fog lights to stay on when the high beams are on. If you are using the same circuit to run your fog lights, then I'd think it would apply. If that's the case, then having your high beams on might make it seem like your fog light switch isn't working.

 

This appears correct to me. I think the BE/GY wire simply provides a signal to the BCM to turn on BE/BK output wire. I don't think it actually carries the current load for the lights. That load I believe only goes directly from the BCM to the lights on the BE/BK wire. The BCM monitors that output current, so as long as the added lights' load doesn't exceed what the BCM expects, everything should be good.

 

So I ventured up to the dealer last night to talk with the service manager, showed him the schematic, confirmed that the OE button HD used is just a standard latching push on/off button. Both he and his senior tech verified both the schematic was correct and the latching push button I will be using will work. Neither where 100% sure whether I needed a flash or no, so I will put a meter on the lines to see how power flow looks and whether it changes when the high beams are activated. Hopefully the lights get shipped soon, back orders suck.

 

I built my harness that plugs into the L/H Switch Pack harness and uses the three connection points shown in my original diagram. So I plug the harness in and before connecting to the connector, I attempted to check the wire coming from the P&A Relay for 12v when the bike is powered up. I received no voltage signal or change between the high beams being on or off. Needless to say I was a bit confused, but after a few hours of pondering this I came to the realization that I am not going to get 12v off the relay because I am not using the power side of the relay, I am using the switched side. Meaning that when the relay gets power from the R/Y ACC wire, it is going to cause the relay to close the switched side just allowing a minimal signal to pass to the Switch Pack switch, which in turn when pushed "on" will send that signal to the BMC telling it to send 12v to the AUX/Fog lamps. Since the switch has a built in light that would turn on/off when 12V passes thru it, this signal would not be powerful enough to light that indicator. So it looks like I will need to tap off the turn signal harness connector that I need to splice in for the fog lights and send that signal to the switch so it illuminates when the lights are on. In the diagram below, this new split-off is pointed to by the green arrow. Good thing is that if my theory is correct, I can add this wire, push the button and determine if I need a flash or not. Since I don't have the fog lights yet, I do have a lamp in the switch that would illuminate telling me that the P&A Relay is switching the circuit, the switch is receiving the signal from the relay and sending it onto the BCM and in-turn the BCM is providing power to the limp/lights. If I get nothing, then it should "in theory" mean that I just need to get the BCM flashed, answering my question. IAnother answer that would help me out, is knowing what kind of signal the Relay is sending out to the Switch Pack, then I would know what to look for there rather than "hoping" my theory is correct or not. I also used arrows with numbers next to them to show the order of how my theory start with the BCM providing the relay with power and ends with the lamp/lights getting power.