Does anyone know why the neutral switch line goes to the turn signal / wireless security module?

 

Because the Clutch Lever Starter Safety Disengage switch input is also located there. If the bike is in neutral it will allow a start without the lever being pulled. If it does not recognize the Neutral input signal then the lever has to be pulled in.

 

Makes perfect sense.
I had seen references to 'flashing neutral light' in threads about the security aspect of the module(s).
Do you know if the module is capable of output as well or is the neutral switch the only activator of that line?
(And thanks for a really fast answer)

Mike

 

Not sure what you are asking. The TSSM/HFSM has 12 wires including a serial data line.
The neutral switch should be the only thing on that particular circuit except that it does Y off to send a signal to the indicator light.
The 12 lines are as follows:
1 Battery
2 Ignition
3 Serial Data
4 Neutral Switch
5 Left Turn Feed
6 Right Turn Feed
7 Right Turn Switch Input
8 Left Turn Switch Input
9 Start Relay Control
10 Clutch Lockout Switch
11 Alarm Signal
12 Ground

If your light is flickering then I would suggest removing your N switch and cleaning it or replacing it. This disrupted signal from the N switch will affect the TSSM/HFSM when trying to start the bike. It can't determine if it is in N or in gear.....and thus can't decide whether you need to pull the lever in or not. Very seldom is the TSSM/HFSM the problem...so if you are looking for the flickering light....the switch or connections at the switch will be your culprit.

 

Sorry, should have started with a 'what am I actually looking for' paragraph.
Apologies.
My Mrs. bought me a Motor Trike mechanical reverse for my '12 Ultra.
The kit comes with an interlock mechanism which monitors the included reverse switch, the neutral switch and provides an interrupt to the engine run line on the right hand grip.
The circuit's only function is to kill the engine if you try to put it in gear and also reverse at the same time.

(The reverse is a separate set of mechanics engaged with a separate lever)

There are several issues though.
The circuitry uses two full sized ISO relays and associated sockets which pretty much fill the cavity under the right hand side cover.
The circuitry does not let you know, or the bike know, that it is in reverse so the neutral light can be on and if the clutch is not pulled the bike starts going backwards on start.
The circuity interfaces tiny, awg 22 looking wires on the bike, with its own large insulation awg 16 wires.

My thoughts were this:
I can redesign the interlock circuitry to:
Be 1.5 to 2.5 square inches of PCB, eliminating the glom of relays under the side cover and recovering precious space for other use.
Provide a better interface than trying to make a 14-18 awg bullet connector stick on the end of wires almost too small to see. (per the Motor Trike instructions)
Flash the neutral light if the bike is in reverse, leave it on if not or kill it if it is in a forward gear.
If it is in both reverse and forward, I would inhibit start and possibly change the flash rate.

The service manual is not much help on what is in various 'black boxes'. The dealer echoed the manual. My next option was to go the this forum and ask advice.

If the Neutral light was used to, say for instance, flash a code for a security module action, I would have to rethink the use of the light as another indicator.

Since, at age 58, this is the first I have ridden since age 18 and my first Harley ever, I wanted to presume nothing.

Does this make sense?

m

 

Yes...i think? The N switch just provides a contact to ground when the tranny is in N. The tan wire comes from the TSSM/HFSM to the switch and the black wire at the switch is a galvanic ground. So basically what happens is that a spring loaded ball inside the switch drops down or pushes up completing the ground circuit and the TSSM/HFSM recognizes the ground connection.

So if you interrupt the ground connection at the N switch the TSSM/HFSM will not allow the starter button to activate it's relays-circuitry and engage the starter unless the clutch lever is pulled in. And the Clutch Safety Starter Disengage switch (clutch lever switch) just overrides the N switch to prevent starter activation while in gear.

Help any?

 

I think so. The presumption is that the TSSM/HFSM is input only. That means all I have to do is ground the neutral line through a relay contact or a transistor/fet and I can add some needed info to the light. I can also do it in < 10% of the existing circuitry bulk.
Only remaining decision is whether to have the circuit insist on a clutch lever pull if in reverse. (Flashing neutral could mean stuttering starter if someone were not paying attention)

I appreciate it.....

Thanks, Mike

 

I added a line to my last post after you had responded regarding the clutch disengage override.

And yes....power is supplied to the N light from a source and the N switch also provides grounding for that circuit so the light will illuminate. And yes again....if you use the N switch to pulse-blink the N light then the starter will interrupt as the light flashes or the lever is pulled in to override it.

Now not being an electrical genuis here....i dont know whether...dimming the light as opposed to actually breaking-blinking the circuit will get you what you want.

 

Two ways to dim the light. PWM - Pulse Width Modulation. This switches the line on and off fast enough that you can't tell it is being turned off. End result is dimmer looking light. The second is actually sending a lower voltage. Could be done by switching a resistor to ground in lieu of the switch.
If the input to the module is a relay coil, either might work if I knew what the pull in voltage was. If it is digital, one way would depend on how the module is programmed for intermittent inputs, the other would depend on the logic family used. Different chips switch from low to high at specifically different voltage levels.
One thing I would have to watch for, if Harley finds a cheaper way to accomplish the same thing and I ever have to replace the module, the new module may have different circuitry all together.
Will have to give it some thought. Sometimes the best designs are dependent on figuring out what might change or happen in the future.
I will say that after digging into the electrics, they are a lot more complex than I originally thought they would be. It's been interesting.

m