Signal Lights Don't Work. Signal Cancel Unit Bypass?

[Zooma]

Hello Everyone,

I have a 1990 RZ350 (Canadian Model). I decided to get it on the road because it only has 2900km. on it, and it seems such a waste not to use it. I have everything cleaned up and working perfectly, not that it needed much because it is basically a new/old bike. I am pretty handy with the mechanical stuff, but electrical troubleshooting is definitely a weakness.

I need some advice on diagnosing and fixing my signal light issue. My knowledge of motorcycle electrical systems is pretty basic, so it would be helpful if you can explain things in beginner level terminology. I essentially understand how these systems are supposed to work, but I don't really know how to go about troubleshooting.

Here's the scenario:

-None of my signal lights work. They will not light up at all.
-All other electrical systems on the bike function normally, but the signal lights will not light up.
-The fuses are all fine.
-I opened up the signal switch box, and everything looks fine.
-The relay seems to be functioning properly. I removed it from its cover and the aperture activates according to the control inputs of left, right, and cancel, respectively.
-The bulbs look OK, but I have not tested them individually. (I don't really know how).

Here are some questions I have after looking through the forum in search of solutions:

-It seems that the Signal Self-Cancelling Unit is a definite weakness, and even if mine is functioning properly (which I suspect it is not), I would like to know how to bypass it. I found conflicting information on the forum, and would like some clarification. One post said that the 'Unit' can simply be unplugged, and another said that it could be bypassed with a jumper wire. Which is it? If it need a jumper, please explain how to do this, because I want to be 100% sure before I attempt something like that. I'm not looking to create additional electrical troubleshooting challenges for myself.

-The relay is obviously getting power, but the lights will not turn on at all. How can I determine whether it is because they are not getting power, or if it is a result of a faulty ground?

- If it is an insufficient ground (which was the case with the CDI), where should I look on the motorcycle for ground wires that are related to the signal lights, I couldn't tell where they were.

I would really appreciate some helpful advice on this, because as soon as I get the signal lights functioning, I can get the bike on the road.

Thanks

[tacky1]

Hi, You can simply unplug the self cancelling unit, There is no jumper or one that I know of to bypass it, One of my bikes was having problems and I just unplugged it and it works fine now.
The jumper is usually used to bypass the side stand switch..

[Zooma]

Thanks for the straightforward answer tacky1, that is potentially useful information regarding the sidestand unit. I will remember that if I have issues in the future. The problem was definitely the self-cancelling unit. I understand that you do not require this explanation, but I thought it might be helpful in the future to other people who find themselves in a situation similar to my own.

I was able to find a schematic online and deciphered the layout. It is actually quite simple and straigh-forward, which is essentially that the power goes from the battery, to the relay, to the self-cancelling unit, then to the lights. Here was the solution: I unplugged the self-cancelling unit and tested the signal lights, but this had no effect. Based on information gleaned from the schematic I put a 'jumper' across the middle two male prongs in the harness that goes to the self-cancelling unit. The wires are Y/G (Yellow-Green) and Black. With the jumper on, I closed the circuit by selecting a turn signal. The relay rattled, and the signal lights fired up and operated normally, albeit without a self-cancelling feature (which is fine with me). I removed my jumper from the circuit and tested the signal lights, and they continue to function normally.

Thanks for the help, and I'm relieved that this was a successful electrical troubleshooting challenge.

[75RD350rider]

Good info
I rode mine this morning after some down time for repaint and upgrades and the turn signal switch is sticking and intermittent. I ordered a spare switch and will attempt to take mine apart again to see if I can get it clean enough to work.

[75RD350rider]

Can anyone enlighten me as to the location for the self cancelling box? Bike is a US spec 84 RZ. My switch is intermittently working so I ordered a spare from flea bay. I was thinking of finding the box and disconnecting it per the advice given here in the interim to see if my problem is actually the switch or the box.

[two-stroke-brit]

i think its under the tank on the left hand side as you sit on the bike.
mark

[JonW]

It should be obvious which one it is, look for the shape, its under the tank as Mark says.

If anyone in Aus needs one, Ive a few here somewhere I think... post would kill any deal to the US I suspect.

[75RD350rider]

Thanks!

[75RD350rider]

Pulled the tank.
Located the offending box right behind the coil. Unplugged the box per instructions here and the signals work like a champ!!! Taped off the cannon plugs and Bob's your Uncle.
Thanks for the education. It is a odd shaped rectangular box just aft of the ignition coil on the left side. I have a spare lh switch coming that I dont need but it is always good to have spares...