Hazzard Lights?

[Adventurer]

I'd like to install Hazzard Lights (aka Four Ways, aka Flashers), on my 1992 Honda CB750 Nighthawk, as I use them often to alert other drivers of hazardous conditions (or if temporarily driving below speed limit), when driving our automobiles and often wish I could do so on my motorcycle, too. What's involved? Is there a reliable and easy DIY kit for this? My turn signals are still the standard OEM style, incandescent (non-LED) bulbs (unlike my LED headlight).

[Bob H]

I have never attempted that.

[Larry Fine]

Do you just need a wiring diagram, or do you need more?

Do you want it to work with the key off or only with it on?

Are you likely to want to convert to LED turn-signal bulbs?

[mollusc]

My NC700X came with factory hazard flashers, which worked when the key was off.  When I switched to LED bulbs for my turn signals I also had to change the flasher unit, and the only one I could find will only work with the key on.
Nighthawk wiring is probably less complicated than a newer bike, but it's nevertheless going to be something of an undertaking to get to a functional stage.  It will definitely require cutting and splicing the original wiring.
Doing a general internet search shows that this is not an uncommon question, and most of the references to kits seem to be from a long time ago -- I guess from before it was standard to include hazard lights and there were more bikes without them on the road.  I did find this though:  https://www.customdynamics.com/metric-4-way-hazard-kit
I have no affiliation with that seller or any experience with the kit, and it's hard to tell what it actually includes from their photo, but it might be worth investigating.

[Larry Fine]

The Nighthawk has a single turn-signal indicator for both directions, which needs to be re-wired to work properly with LED bulbs, which is why I asked that question.

It's funny that the "metric" kit mentioned above only shows fitment for Harley and Indian bikes. You can get the materials needed for this for much less than $50.

Once My questions are answered, I can suggest parts and draw a diagram. I helped one of my friends add 4-ways to his BMW, with a lighted switch that flashes.

[mollusc]

Strange that the later CB750 has only a single indicator on the instruments -- the 700S has one for each side which makes things a bit simpler.
To be honest, I didn't look at that kit in enough detail to spot that it referred to Harley and Indian.  I don't think anyone would consider either of those to be metric bikes.

[Adventurer]

Do you just need a wiring diagram, or do you need more?

Do you want it to work with the key off or only with it on?

Are you likely to want to convert to LED turn-signal bulbs?

I was hoping for a kit with wiring diagram I guess. No current plans to convert to LED. Not sure if I'd want to work without key or not, but I guess on my auto's it works without key. Open to suggestions in that one.

[Larry Fine]

Messing with the wiring on a bike is not something to take on if you're less than sure about what you're doing. Do you have a shop manual?

If you want a kit, check eBay and online bike stores. I'll be happy to look at several you want an opinion about if you post links to them here.

Any weatherproof D.P.S.T. switch will work. Double Pole to keep the left and right lights separated normally, Single Throw because you only need on-off.

The main thing you need to choose is what style of switch you want, where to mount it, lighted or not, or use the existing signal light, no light, etc.

Wiring diagrams are easy. Look at the diagram below. The existing wiring is black, and the added wiring is red along with the new switch.

Since you want it to work without the key, you would provide a fuse and separate flasher instead of connecting to the exiting flasher as shown.

The advantage to doing this is they will work any time, you can take the key. The disadvantage is they will work any time, you can drain the battery.

Click to enlarge:

[slodoug]

should be doable. the above diagam will work, i got a switch off ebay and added it to my 83 cb650SC (also added it my 81 m400a). get a digital relay
https://www.superbrightleds.com/lf1-s-pin-universal-motorcycle-electronic-flasher-universal-pin-motorcycle-flasher

and a button switch.
https://www.ebay.com/itm/126108686625

I like to make Y bullet connectors to splice into my existing right/left side flasher circuits rather then get messy and splice them. don't just crimp, solder them. The only glitch on my NH was when my turn signal is on, the button light comes flashes, but no biggee. I zip tied the relay near the front fuse box.