new to me 1976 KZ 900, wires go where?

@Mikaw,
Ok so the brake light warning should be mounted there correct?

I can't see any readings (the only thing I can see on the wiring diagram that looks like the is a brake light failure switch)

@wookie58, Mikaw, F64
both wires disconnected from the left coil, probe on positive terminal to probe on mounting lug, there is no reading, with key turned on or off. 

Ok, let's pick this back up tomorrow as it's after midnight here in the UK

oh wow!! Thanks wookie58! yes head to bed! I'll keep at it but getting cold out there again. It's now 15 degrees and snowing. The wife and I getting a freshly made pizza in then oven!! Thanks again.

wrote:

@Mikaw,
Ok so the brake light warning should be mounted there correct?

I don’t understand this statement. It looks like it is mounted there. It should have a 3 pin (wire) connector. If it’s disconnected your dash brake light will be on and the rear brake won’t work. I think. 

Hi Mikaw,
The brake light warning is mounted under the left coil and attached to one of the coil lugs. I was wondering if maybe it wasn't supposed to be mounted there? That is all. I thought it may have been my source of issues and maybe should be mounted elsewhere.

It is in the correct place. Should be on a thin sheet metal bracket pinched between the coil and the frame.

I’m by far a electric diagnostic expert. I’m not sure were wookie58 is getting that the coil voltage is different. This looks like your coils are getting the same voltage. Am I missing something?


Turn on ignition.
Red probe on positive battery post.
Black probe each coil's negative terminal. left coil voltage = left coil voltage = 1.42 v and slowly dropping  right coil voltage = 12.05 v

Rotated engine till other points reach their TDC and open.
Red probe on positive battery post.
Black probe each coil's negative terminals again, left coil voltage = left coil voltage = 11.42 v right coil voltage = 1.60v and slowly dropping

 

wrote:

I’m by far a electric diagnostic expert. I’m not sure were wookie58 is getting that the coil voltage is different. This looks like your coils are getting the same voltage. Am I missing something?


Turn on ignition.
Red probe on positive battery post.
Black probe each coil's negative terminal. left coil voltage = left coil voltage = 1.42 v and slowly dropping  right coil voltage = 12.05 v

Rotated engine till other points reach their TDC and open.
Red probe on positive battery post.
Black probe each coil's negative terminals again, left coil voltage = left coil voltage = 11.42 v right coil voltage = 1.60v and slowly dropping

Hi Mika’s, the above shows 0.63v difference between the two coils when the points are open. Given that both coils share a feed this is significant over such a short distance 

 

No eBay APP ID and/or Cert ID defined in Kunena configurationWookie58, understood, but without know if battery voltage was a constant how can you make that call. Battery voltage wasn’t noted at the beginning of each test. Unless I missed the note. Rscone11 even mentioned “and slowly dropping”. His battery has been under unusual circumstances. There has to be a point in engine rotation we’re both points are closed, would that be a good place to test. Coils condition would be consistent. A great test tool would be a constant DC power supply. Take the battery off line and connect leads to a plugged in constant voltage source. 

Hi Mikaw, I completely agree with you. Many of the electrical issues suffered by guys on this forum are due to corrosion resistance, let's face it these bikes are nearly 50 years old now and none of the connectors are effectively weather sealed from factory (in some cases this can be lot's of small loses at each connector in a circuit which add up by the time you get to the last consumer) It would be great if everyone had the skill or budget to complete a full re-wire but in most cases that's not practical, cost effective or "original" for the restoration guys.
My next suggestion for rscone11 would be to disconnect the 2 coil feeds from the yellow and red and run a lead (ideally with a 10amp fuse in it) from the battery positive (Assuming the battery has been charged back up) directly to the coil feed (BE CAREFUL FOR HOW LONG TO AVOID COIL DAMAGE) then crank her up and check for a spark.
A spark under these conditions would give the ign system a tentative "thumbs up". If the solves the issue then I would suggest a by-pass relay to feed the coils as has been mentioned on other posts (this is quicker and easier than tracking down lot's of small resistances throughout the circuit which may not be impacting other consumers with lower current requirements)

With regards the "clicking" looking at the wiring diagram there isn't much (especially on this circuit) that can do that. One thought I had was that if the starter button isn't fully disengaging it won't pass enough current to fully engage they relay and operate the starter but could be enough to "kick" the solenoid. This would be easy enough to check by seeing if there is a small voltage being applied to the small black wire on the starter solenoid.

Ultimately the wiring on these bikes is not complex but the issues caused by the ravages of time can be tricky to pin down