'78 3 prong flasher relay help needed

[Westfalia]

The stock 3-prong flasher is partly working. When activated it buzzes and turns on each side when selected but won't blink. I can get it to blink once by tapping it, but that is it. This bike sat(inside) for 30 years so I assume the contacts are stuck. Can I open the can and "adjust" them or at least hit them with contact cleaner?? Is there a write-up here on the site to switch over to a two-prong unit? Still standard bulbs and not LED. Entire bike bone stock. The relay is original Nippondenso FN257C labeled 12.8v 85CM 27w X 2 +3.4v

I checked the search and archive and did not find much other than the flow chart that points to replacing the relay which btw are made out of unobtainium, apparently. BTW, does a '78 have a "self-canceling" circuit and box? If so where is it?? Thanks for any info!

 

[gggGary]

Yes it has canceling, the distance measuring is in the speedo housing. thinking the canceling unit is under the tank.

77 wiring diagram, pretty much identical.

 

[gggGary]

Never (had a reason to) open one, should be possible.

 

[Westfalia]

Well, I opened it. Very simple. Cut back the plastic wrap and bend back the 3 small crimps and the works slide right out. Here is a video and you can see what it's doing. All the internals look brand new. No broken wires, contacts seem clean and corrosion-free. I'm sure I shouldn't be tapping it. There is 12v to the brown wire, but maybe the bike needs to be running to make enough voltage to work properly.

Is the turn-canceling box gray in color and under the seat? The shape in the wiring diagram above seems very similar.

 

[5twins]

The gray box under the seat is the reserve lighting unit. The turn signal canceler is a rubber encased box located just behind the steering neck. Here's mine that has been "relocated" slightly to clear my new coil (I bent the bracket up and placed the unit on top of it) .....

 

[toglhot]

$9 Aust for an adjustable one on ebay.

 

[Its been a long time]

The gray box under the seat is the reserve lighting unit. The turn signal canceler is a rubber encased box located just behind the steering neck. Here's mine that has been "relocated" slightly to clear my new coil (I bent the bracket up and placed the unit on top of it) .....

View attachment 260243

Thanks, I was wondering where the flasher cancelling unit was located.

Do they ever give any problems? They're all coming up to 50 years old now and I guess the flashers don't work if the cancelling unit goes bad.

I think the flasher relay is up there behind the steering tube too?

 

[gggGary]

Yes not running with less than stellar battery, connections, switch contacts etc. they won't always flash. By design the stock flasher is load sensitive. Not flashing is an indication somethings not right (like a bad bulb) At 40 plus years old all the electric is due for a bit of clean up, love.

 

[Westfalia]

I just realized my "video" did not work. Apologies. I'm going to try again. Here is a link for YouTube. Buzzing blinker relay

 

[Niels B]

I had the same problem with my relay, it turned out I had a weak battery and bad ground, after replacing battery and ensure good ground ( on your turn signal too) it worked fine. Mine doesn’t have the self cancelling unit though

 

[gggGary]

Disconnect turn signal wires in the headlight bucket, does the buzzing stop?
A common problem is dark green, chocolate brown. and black wires mis-connected.
I'm guessing there's a short to ground somewhere.

 

[Melnic]

I pulled mine apart too before I had bike running thinking I could get it to flash because it would not flash with just the power on and bike not running.
I got it to flash w/ the charger plugged into the battery w/ it charging and I recall battery was 13V.
When I got bike running, my alternator was not charging so voltage was still really low and it would not flash.
I did a lot of work to clean up all the contacts that feed the voltage to the flasher relay. (ignition switch, connectors in the headlight, flasher relay contacts/connectors etc)
With all that fixed, it only flashes w/ it running but I have yet to have it NOT flash while running.

I purchased a 3 wire LED flasher that was SUPPOSED to work w/ incandescent bulbs but but it was not plug and play, I think there are flashers with the 3rd connection that are either 12v and ones that are ground.

In my 83 XJ650 the PO installed LED turn signals and it has a different flasher plugged in w/ a dial that sets the blink rate. I have yet to pull it to see A) what is the part # so I can get another B) will it work plug and play on my XS650.

If you know about flashers, it uses heat to get the contact to bend away from the terminal that lets light stay on. When it bends away, it cools, then comes back to make contact.

 

[Wingedwheel]

I replaced the flasher on my ‘76 but it was not plug and play. There is a thread about doing it. You have to switch a couple of the wires around in the flasher plug. It was very easy to do.

 

[5twins]

The self cancelling units on both of mine are hit and miss - sometimes they work, sometimes not. I don't know why that is. I just watch the indicator on the dash and cancel them myself if need be.

 

[Westfalia]

Thanks for the great suggestion, everyone!

I had the same problem with my relay, it turned out I had a weak battery and bad ground, after replacing battery and ensure good ground ( on your turn signal too) it worked fine. Mine doesn’t have the self cancelling unit though

The battery is brand new, all bulbs are correct wattage and are clean and working. I'll go back and check all the grounds again. Come to think of it the upper mount is off due to us getting the condenser off, so not sure if that needs to be installed to complete the motor ground??

Once we get this bike back running reliably(was waiting on a new condenser), I'll come back and post what happens. Thanks again.