Auto canceling turn signal diagnosis

1981 KZ750 H LTD

The motorcycle came from the factory with automatic turn signals and ever since I bought the bike they haven’t worked. I decided after riding a friends Harley Davidson sportster they were quite nice and decided to repair mine. Beginning my diagnostic I found out how they work and began to work my way through the system. 

The speedometer has a distance sensor that gets continuity 4 times for every complete rotation of the drive cable. Using a multimeter, I confirmed my speedometer distance sensor was working properly.

The switch itself works manually just fine, however to test the solenoid inside the switch housing, power has to be sent to the white/green wire coming from the auto canceling module. By jumping this wire, it will trigger the solenoid and shut off the turn signal. so I have confirmed the issue is not inside of the switch. 

I have also checked for power to the yellow wire and ground to the black/yellow wire and all checks out there. Power is only sent to the module when the switch is placed in the A for automatic position and it does indicate battery voltage at the wire. 

The blue/white wire sends current to the switch from the module, once the turn signals are turned on, in either direction, it will send continuity back down the red/white wire to the module. This I what I believe begins the modules 4 second count down timer until it begins to analyze the distance sensor however I do not know for sure.  

The only other wire is a white/red wire that goes from the module to the switch. I am unclear on the purpose of that wire however it does get continuity all the way to the switch so I have reason to believe the switch is properly working so the white/red wire is working as well. If anyone knows and could provide the guidance I would greatly appreciate it.  

According to the manual, if the wires all test well then it says to replace the module. Thus I did exactly that. After days of waiting for it to arrive it finally does. After installing it, nothing has changed. It still does not work. Can it be possible that 2 modules were bad? Is the auto canceling module known to go bad? 

I’m interested in this, because I have the exact same bike, only it’s a 1980 instead of 1981.

Anyone? 

Will have a look when I get a chance and see what I can suggest - do you have a sharper image of the wiring diagram (I have old eyes)

By Kubik:  I’m interested in this, because I have the exact same bike, only it’s a 1980 instead of 1981.

From the diagrams at Partzilla & FSM the 1980 KZ750-H1 does not have the turn signal device.
The date of mfg isn't necessarily the model year. As w any vehicle, a motorcycle made in 1980 could be an 81 model.

From the Kawasaki 80-85 KZ750-4 FSM pdf chain drive. edited:
Click a couple of times to enlarge. or open in a new window & click to enlarge (it should be fairly big).

Wookie, here is the link to the copy posted on the forum here. Should be better for you. 
kzrider.com/filebase/download/79-kz750-e...981-colour-schematic

My 1981 bike was made on 11/80 so anything is possible. The biggest difference I have seen so far is a change in the connector for the turn signal module. Just make sure the connectors are the same when buying a replacement module.

The KZ and ZN 1300 models had the same (or very similar) self cancelling system - they also had a second switch to disable the self cancelling.  Did the 750 have the extra switch?

Cb900f, yes the KZ750 has a switch that will transition the turn signals from automatic to manual to hazards. By placing the switch into the A position, power is sent to the module via the yellow wire. When the switch is in the M position, no power is sent to the module. 

Ahh, ok.  I re-read your original post and saw that you mentioned the manual and automatic. 

Not clear exactly what you did, but I think you bypassed the switch, and put voltage directly to the solenoid, and it worked.  My guess is the circuit feeding that solonoid is not letting enough current through - maybe dirty connections and or switch contacts.

 

Cb900f, when I bypassed the module to send power to the solenoid I was simply checking to ensure the solenoid would function. the power was sent from the battery to the white/green wire that triggers the solenoid. The issue with the dirty contact guess is that when I sent power from the battery it was from the module connector. Meaning as far from the switch as possible and the battery current made it with enough power to trigger the solenoid still. It makes sense that the module would send a shot of battery voltage to the solenoid so I don’t believe that is the issue, however I will gladly clean them all off again and reapply dielectric grease. 

Ok Elfarm please do the following checks (I want to establish what the signals to and from the module are) and I will put a test plan together on "Boxing Day" as the next couple of days are going to be busy

Using a voltmeter with ign on, turn signal switch in the rest position and combination switch in the "A" position
red probe to battery positive and black probe to red wire at module what is the voltage -
black probe to battery negative and red lead to red wire from module what is the voltage -
red probe to battery positive black probe to blue/white at module what is the voltage-
black probe to battery negative and red lead to blue/white at module what is the voltage-
 

Wookie, I will do the test when I get home but I have one question. At the plug there is a red with white stripe and a white with red stripe. For the preliminary test, which one do you want me to get voltage from?

Also looking back at the service manual under 1981 supplementary, it looks like the tests you recommended align with the chart provided at the bottom of page 276. I will attach that so you don’t have to go look. 
If this is the test you want me to preform then I have already done them and the results I got were consistent with the manual.