Turn signals wont light up at all?

[Greasey Fingers]

Been trying to get the turn signals working on a bike ive got here, its a 1979 SOHC xs250. Ive got all the electric working properly EXCEPT the turn signals. Im getting nothing at all from them, they wont light up at all.

Ive tested the following;

-Fuses are fine

-switch on the handle bar works (continuity test)

-all the turn signals light up if I give them direct power

-general continuity tests to do with the signal system and everything we tested seems ok

-swapped out flasher relay with other one and still no joy

-swapped out that little black box with other one still no joy

Not sure what im missing here? Battery has charge and powers the horn, starter motor, brake light, head light, etc with no problems. Im pretty sure the bike doesn't have to be running for the indicators to work.

Im stumped Any help or ideas are appreciated!

 

[xschris]

Is the harness grounded?

 

[Greasey Fingers]

Hi Chris, I didn't check that. Where abouts is the ground for the harness usually? I hope that's the issue

Btw all the other electrics work perfectly and the bike runs well. If the harness wasn't grounded properly, is it possible it would only effect the signals? Because like I said everything else is great.

 

[xschris]

On the 400 it's next to the battery(on the box it's self). Are the ground wires to the lights actually grounded, I would also check for that.

 

[Greasey Fingers]

Ok, looks like the harness is grounded fine, the loom definatly has power going through it because everything else is working fine. The signals look to be grounded fine too. I lit them all up one by one from the harness, via wires in the headlight bucket.

Its not going to matter if they are mounted to the bike for testing purposes is it, as long as they are all connected properly?

 

[kindest]

do you hear the flasher clicking when you turn the signals on?

 

[Greasey Fingers]

Nah no clicking, no sounds at all. Its like its just dead!

 

[xschris]

They don't have to be mounted to the bike to work. But the ground wires all must be attached to the stems on the signal in order to work.

 

[16VGTIDave]

Have you tried replacing the flasher relay with a jumper wire? This will have the turn signals come on steady if it is the problem. If that doesn't produce any results, try bypassing the the switch at the connector in the headlight bucket.

 

[Greasey Fingers]

Cheers Dave good idea! Ill give it a go, this is really stumping me they should work...

 

[willem]

Try adding an extra ground wire to the flasher relay if the jumper wire trick works. Just attach a wire from the earth pin on your relay to a nice bolt on the frame.

 

[Greasey Fingers]

Hey probably a dumb question, but what wires do I jump. I have three wires, brown, brown with a white stripe and white with a green stripe...

 

[willem]

IF it's the same as on the SOHC xs400, the brown goes from your relay to the signals, the brown/white comes from your handlebar switch, the white with green is your ground. I would try jumping the two brown ones

 

[Greasey Fingers]

Cheers mate! I tried that and no joy

 

[willem]

do you get a voltage reading at your lights that way? Or at the place you short the relay?

 

[TimmyT]

Ive been running through the rickets trying to get to the bottom of my issue as well. I also now have 2 flasher relays that im sure both are good and 2 flasher cancel relay that are both probabally good. My lights were working... then they stopped working, and during a troubleshoot to iscolate the issue I had them working again for a brief period. The signal bulbs need to be 12.8v 27w and 12v 3.4w in the indicator panel to all function properly. If one bulb is dead this can affect the draw of all lights since they are single filament. IF your bulbs are out of spec or if some are blown they all shut down, if your indicator panel bulb is burned out or if there is an issue in the control panel wiring for the signal lights here then none of them will work. I know mine are wired correctly because I had them working ... my non functioning issue had become a troubleshooting for what the intermittent issue is. To me there is a bad ground somewhere I have to track down or add a ground to frame from the relay.

The service manual has a section on electrical troubleshooting in this area to isolate the issue from flasher relay, flasher cancel relay, flasher switch, and flasher indicator bulb. When I got mine to work after I thought they were toast I had removed the spedo cable and I was jumping some wires. ... the trick is to make sure the wires have continuity where they should and not where they shouldn't.... wires are good...now isolate components and so on. Also check the fuses, I blew a fuse while jumping the wrong wires but at least I know the fuses work!