'91 HD Springer Turn Signals

[mlucio]

Can anyone tell me exactly how the turn signal module that is located directly below the speedo works?

Trying to help a buddy out with his bike. Got a manual and it mentions this module needing a signal from the speedo. Want to know what that signal is and how its generated?

Any info on the subject would help really. Thanks

[ajInMs]

Do you just want to know how it works or is there a problem that you are trying to trouble shoot and solve?

[mlucio]

A little bit of both I guess, if you're offering. lol I really just like to know how things work, helps me figure shit out faster. Knowing this signal is the answer to my problem isn't enough, I need to know exactly what this signal is. I guess its just a pet peeve.

I'll elaborate a bit more on the situation. My buddy bought a bike about a week and a half ago now, got it registered and all this stuff because of some requirements by his bank and loan. It needs to be inspected within seven days or registering, he has no turn signals, because the PO took them off, but left all the wires and components to put them back on. So I researched lightly and found that the module needs a signal from the speedo to work properly. One problem now, is that the speedo cable isn't spinning and therefore the speedo isn't generating this "mystery" signal.

[punkrod]

The speedo has a "switch" that triggers when the bike goes from 0-30mph which kills the signals. I can't remember what kind of signal it sends though. I'll dig around my notes and see if I can find it. I think it momentarily sends voltage (13.8v) to the module.

[mlucio]

YES! this is exactly what I thought it did. Thanks a lot.

[ajInMs]

I was just curious. I just got through troubleshooting a bunch of electrical a 96 Sportster I bought 3 weeks ago. The PO had just put a new speedo/odo on it and it didn't work. He ordered and put the new one on because the other one didn't work. Well...the new one he put on didn't work either...BUT my turn signals worked properly. They flashed as they were suppose to and then cancelled when they were suppose to.

I like to know this stuff to and was also thinking the more information you put out there about the problem you are trying to resolve the more others have to go by to be able to assist you. I may not be a whole lot of help in some areas but there are a bunch of dudes hangin' around this joint who can and will if you let them know exactly what's going on.

[mlucio]

Punkrod one more question. Is the canceling module also the unit that makes the signals flash? Because we've got everything working, just not flashing.

[punkrod]

Does the module look like this?

The module performs all the flashing and function of the turn signals.
It will only flash if it has the same impedance as the stock lighting, 2 1156 bulbs and the factory indicator light, about 13 ohms total. If you're using small aftermarket marker lights then they won't flash. Badlands and other companies make a little modulator that makes the little bulbs flash or you can add a big 10 watt resistor to make up the difference in ohms.

[mlucio]

Yep that's the culprit. And yes, my friend picked up a little license plate frame with LED's so theres the problem I guess.

[mlucio]

Thanks a lot for the info man, appreciate it.

[punkrod]

Thanks a lot for the info man, appreciate it.

No problem. Always a pleasure anytime I get an opportunity to use my 90's H-D era knowledge.

[blackjx]

Slight technical correction. The white/green wire gets a signal from the speedo after a given distance, not speed. Otherwise, you could never signal when riding above 30 mph.

[blackjx]

And, BTW, the cancel module will cancel the turn signals after a given time anyway, so if you just left the speedo signal disconnected, it'd still cancel after a certain time. Just in case the OP wants to run an A/M speedo or something.