Modified Electrical Wiring Diagram

Hello all!

I have been having some electrical problems with my 1980 XJ650 and found that all of the wiring diagrams I found on here (and in searching online) did not suit what I was looking for. I decided to create my own, and would like a critique to see if I have everything correct.

I have created a modified diagram based off of the colorized PDF floating around, found in this post:
http://xjbikes.com/forums/index.php?threads/high-res-pdf-of-xj650-wiring-harness-diagram.44033/

In the PDF, I noticed a couple of things that were ambiguous, and the wiring was impossible to trace. My diagram groups the functions together so that there are fewer overlapping wires.

The modifications I have made are:

1. Remove the clutch lever switch (and associated wiring)
2. Remove the side stand switch and relay (and associated wiring)
3. Bypass the diode box for the starter circuit oil light indicator (and associated wiring)

My Diagram:
Link: High Quality PDF



The open questions I have are:

1. I noticed in bypassing the diode box for the oil light indicator that the diode box is relatively worthless because the only other function is to provide a single diode for the headlight relay. (I believe that it allows the latching relay an AC signal from the alternator for the sensing side of the relay input, confirmation of this would be great.) Does my diagram properly remove the other functions box so that I only need the two white wires?
2. My TCI has 8 pins, and I understand what 7 of them do. What is the function of the last pin? On the colorized PDF i referenced, I see that it goes to the side stand relay. Is this another security feature to kill the engine if the side stand is put down while running?
3. The XJ only has one turn signal indicator on the instrument cluster. I assume there is are a couple of diodes in there so that there is no backflow to the other direction lamps, but don't know. In my diagram I have diodes represented for this. Is this correct?

Please feel free to provide ANY input, as I spent waaaay too long figuring out all of this stuff in diagnosing if my bike has any electrical problems.

 

in regards to #3 above, no, there are no factory diodes in the signal indicator wiring, they relied on the resistance in each signal circuit to prevent the signals from all lighting up. oh, and not all xj bikes have a single indicator bulb, a few have right and left indicators.

FU

 

I'm not sure why you would want to ditch the clutch switch and wire it so you could only start in neutral. Doing a rolling restart or starting quickly after stalling when taking off etc. would become slightly challenging.

 

2 things i noticed.
you have a un-fused wire from the key switch to the tail light, works but bad practice.
the rectifier is hot all the time

 

@FtUp, I am a bit confused how the single factory light circuitry would prevent both the left and right side turn signal indicators from flashing if the wiring to both the left and right sides were connected. Maybe I need to take apart the instrument cluster to see how that works exactly....

@jayrodoh, I agree. You are correct. That would be nice. I am unsure of how to wire it properly to the starter cutout relay though. In looking at the stock wiring on the bike, this is a place where I found conflicting information with the factory wiring diagram. If my understanding is correct, on the factory wiring diagram it shows that the clutch lever switch goes through the diode box to prevent the neutral light from illuminating when the clutch lever is pulled. (and this is definitely a good safety feature, you dont want the neutral light to come on every time you pull the clutch)

To modify my circuit, it looks like if i wire the clutch switch from a ground to the starter cutout relay that backflow from the ground would also light up the neutral indicator light, and I don't want that. Do you have any suggestions to prevent this?

@Polock, The tail light goes through the main fuse from before the keyswitch. I think this is the stock method used.
I am unsure how else to wire in the rectifier. I thought what i was showing here was stock. How should it be wired up?

Thanks all! Any more input would be great!

 

Very nice drawing particularly when you show the inner workings of the relays.

Need to be specific on the model as there are some minor differences between them. For example, your version (1980) should not have a side stand switch or relay. Later models have these and also have a diode within the starter cutoff relay.

The smaller wattage bulb for the indicator limits the current through the non signaling side. Therefore, while there is a current path from 12V through the indicator bulb, through the turn signal bulb and to ground, the only bulb that will be visibly lit will be the lower wattage indicator bulb.

The non signaling side turn signal bulb provides the ground for the indicator bulb.

Yes, use a diode as specified in the original drawing in series with the neutral switch, then depending on the model, the clutch switch will either wire though the side stand switch or directly to ground.

XJ's with a side stand switch will have a side stand relay, the relay removes ground during safe conditions (side stand up or in neutral) from the TCI to enable it.

 

you right, i missed the main fuse on the tail light.
your right the reg is wired that way. never noticed that before. it looks like it could go to the center position on the key switch and do the same thing. but if it's not broke, don't fix it