Simple headlamp relay with start cutout

[posplayr]

Thanks for your support

In simple terms that circuit works because the stator voltage can't climb appreciably above the battery voltage due to the way a shunt r/r works. Some current and voltage limiting to the relay would be safer and would avoid having your charging system knock out the relay controlling your lights. As always mount mechanical relays someplace so that they will be insulated from engine vibration and heat.

I just looked at the SSPB circuitry and it would have intact been easier to implement the stator voltage enable rather than a start signal disable. The SSPB is already designed for high voltage transients so even the changes to do charging enable are doable. Not sure there is any benefit if there is headlamp cutout other than hid does not like on off but the one I have doesn't seem that bad. Reminds me to do some testing on it.

 

[Steve]

Ask Steve. He sent me a diagram that was very simple to implement, and it worked just fine. I used a standard 5 terminal Bosch-style relay, nothing special.
I misplaced the diagram since then, but I suspect he still has a copy.

I remember sending it to you, but I can not find it right now.

If you only want a cut-out relay, make sure it is a 5-pin relay with the center terminal 87a, connect it this way:
- Interrupt the wire from the LIGHTS fuse to the headlight (before the dimmer switch)
- Connect #30 on the relay to the wire from the fusebox
- Connect #87a to the wire leading to the dimmer switch
- Connect #86 to the starter terminal on the solenoid
- Connect #85 to a ground.

In this configuration, the relay is relaxed virtually all the time, and power flows through it from #30 to #87a. When you press the starter button, #86 will be energized, which will send power to terminal #87, instead of #87a.

Simple, foolproof, fail-safe.

If you want to use a relay to power the headlight, too, install that one between the fusebox and the cut-out relay.
#30 goes to the battery (with a fuse, of course)
#87 goes to #30 of the cut-out relay
#86 goes to the wire coming from the LIGHTS fuse
#85 goes to a ground.

I can draw this up later, if necessary.

.

 

[posplayr]

I remember sending it to you, but I can not find it right now.

If you only want a cut-out relay, make sure it is a 5-pin relay with the center terminal 87a, connect it this way:
- Interrupt the wire from the LIGHTS fuse to the headlight (before the dimmer switch)
- Connect #30 on the relay to the wire from the fusebox
- Connect #87a to the wire leading to the dimmer switch
- Connect #86 to the starter terminal on the solenoid
- Connect #85 to a ground.

In this configuration, the relay is relaxed virtually all the time, and power flows through it from #30 to #87a. When you press the starter button, #86 will be energized, which will send power to terminal #87, instead of #87a.

Simple, foolproof, fail-safe.

If you want to use a relay to power the headlight, too, install that one between the fusebox and the cut-out relay.
#30 goes to the battery (with a fuse, of course)
#87 goes to #30 of the cut-out relay
#86 goes to the wire coming from the LIGHTS fuse
#85 goes to a ground.

I can draw this up later, if necessary.

.

If you look at the first post in this thread you will see that the performance and function of your two relay solution is in fact fully embodied in the single relay solution you will find there.

That is to say that you will power the dimmer switch directly from a set of relay contacts which is powered from an unswitched (but fused source) .

And cutout the headlamp power when cranking the starter.

Both functions and one added relay, with the headlamp current NOT going through the ignition switch NOR through the fusebox.

 

[duaneage]

Mine works great. 2 parts and no fuss.
Yamaha used that design for years with no problems.
I should add buzzers, lights and an LCD display for current flow and voltage to it.

 

[posplayr]

Mine works great. 2 parts and no fuss.
Yamaha used that design for years with no problems.
I should add buzzers, lights and an LCD display for current flow and voltage to it.

It is a good DIY mod, but not likely anyone would actually design it into a system that way today (I hope).

More current limiting and voltage protection would be most appropriate.:clap:

It also goes without saying that a complement of flashing LED's and buzzers would provide a better user experience.

 

[GalDemSuga]

posplayr

I had some questions on wiring up the single relay to accomplish both headlight power and starter cutout. I have a 1982 GS1100G where the headlight is always on and there is no on/off switch. Do I connect both of the White and Yellow wires from the headlight socket to pin 87 on the relay, which means the switch position itself determines whether I have high or low beam on? I'll be using a 5 pin relay with 87 and 87a options.​

 

[Rich82GS750TZ]

GalDemSuga , Jim/posplayr hasn't posted on the forum for quite some time. He's not likely to answer your question. Which is unfortunate, because his knowledge has helped me and many others for many years. You may do well to start a new thread in this forum with your questions and/or try the search function for similar threads.

 

[GalDemSuga]

GalDemSuga , Jim/posplayr hasn't posted on the forum for quite some time. He's not likely to answer your question. Which is unfortunate, because his knowledge has helped me and many others for many years. You may do well to start a new thread in this forum with your questions and/or try the search function for similar threads.

Thanks for the heads up. Happy 4th