Can anyone identify these wires?

[spills]

1979XS400F

pulled the battery box to look for loose cables/ grounds, as my battery is frequently dying after short trips. Once on the trickle charger, battery comes back to full very quickly.

Up in front of the battery box are these two 4 pin connectors with snipped wires.

The first has intact yellow and blue wires, with two black (or white braided and just dirty?) cloth looking wires snipped. Coming into it looks like Light Blue, Red/Black, Green, Tan?
The second has one white cloth intact, looks like headed toward stator. The three snipped appear to be white / cloth as well.

Both of these tuck into the harness on the other end just under the tank, headed towards the headlight.

ALSO:

see photo of old rectifier that was snipped, and new one in its place.


About to dig through the diagram, but any insight is appreciated.


KM

 

[spills]

so from what I can tell, one of these is the second in on the left of the included section of the wiring diagram.
two wires go to the neutral and oil switch, but what is the other unlabeled picture that green and black go to?

anyone?

 

[BBS360]

That’s the alternator field coil.
If it’s not actually hooked up the battery will never charge, just slowly discharge as it runs.

 

[spills]

So is that down in the alternator /with the stator coil?

I've also discovered that
- the replacement rectifier is wired directly to the battery terminals
- the buss fuses are (3) 30a's and (1) 14a, instead of 10a's and a 20a.

 

[BBS360]

Yes, the field coil is inside the alternator housing and the wires enter with the three stator wires.
The wires don't take a direct route but the rectifier does connect through to the battery.

I'd go back to stock fuse sizes. Any extra load permitted on the wires could cause damage.

 

[spills]

Yes, the field coil is inside the alternator housing and the wires enter with the three stator wires.
The wires don't take a direct route but the rectifier does connect through to the battery.

I'd go back to stock fuse sizes. Any extra load permitted on the wires could cause damage.

Alright, thanks for this. Next I'll get off the case to the alternator and start the rewire back to the old way.

Definitely plan on returning to stock fuse load, as I'm sure this has contributed to all of my electrical problems (intermittent flasher fail, failure to start, headlight dying, etc)

Question though: is it possible to test my original rectifier for continuity before I wire it back in to the harness? Or is this only possible when voltage is passing through it?

 

[BBS360]

It can be tested with a multimeter.
I’d guess the stock one must have been defective if someone spent the time to replace it.
As long as the new one works it should be fine.

The other cut wires make me wonder what the regulator is connected to, if it’s even installed.
Should be attached to the battery box.

 

[spills]

The regulator is still attached to the harness as it should be. As I can currently see, only the plugs to the alternator and field coil have been snipped and adjusted.

So I tested the original rectifier for continuity while it was not attached to the harness, and saw no signal from red to white wires, or from black to white wires.

 

[spills]

So i brought the bike inside and completely opened up the witing harness, attempting to get it back to stock.

2 of the fuses had changed paths, and were bumping into a brown wire with a lot of connection points (also headed to regulator, brake switches, etc) and one of the R/Ws headed towards the electric start switch was actually jumped off of a R/Y which was coming off of the headlight relay.

Also, wirig diagrams only show 3 wires coming off of the RH handlebar switch, while mine most definitely has 4. Just a mistake?

When I closed everything back up, turning the key produced a very bright neutral indicator and tail light, but no electric start whatsoever.

Thoughts anyone?

 

[cutlass400]

I'm currently dealing with the wiring on my bike so can give some insight here. Mine is an 82 special heritage. The starter relay gets its power from the red/white wire from the main fuse. The ground comes from the start switch on the blue/white wire. I had the same issue with not enough wires coming from the RH switch, what I believe was the idea was the start switch gets it's ground from the handlebars then sends it down the blue wire to the starter solenoid. My switch had a black wire coming down the harness but where it connected to the main harness there was no wire on the other side so I tapped into one of the black ground wires inside the headlight and ran it to the black wire in the switch harness which goes to the other side of the start switch. The kill switch also control the red/white circuit so it kills the power to the starter solenoid as well as the coils and ignitor unit.

Basically red/white- anything ignition related, Red/yellow- lighting system, Black- ground. The thicker brown wire that splits into about 3 ore 4 wires going to the fuse block is the main feed from the key switch to the fuses. The main key switch gets its power from the "main" fuse which comes directly from the battery at the starter solenoid.

The Starter solenoid should not be tapped into the red/yellow wire however since it has power on it when the key is on it should still allow it to crank. My guess is your not getting ground on the blue/white wire when pushing the start button to access the switch you have to take the two screws out of the RH switch and you will see where the black wire goes to the start button and the blue/white comes out. It is common for the spring inside the start switch to burn up which makes the switch inoperative I just had to replace mine they sell the button with spring on eBay.

I rewired some parts of my bike 10 years ago and am now trying to get it somewhat back to stock (i was using a separate starter switch for years) and could go back and kick myself for some of the wiring I did. Just finished it up tonight but just know your not alone in the madness. I would recommend saving and printing the wiring diagram whoever made it deserves a metal it's very well done and accurate.

 

[xschris]

Make sure you guys are using the correct wiring diagrams for your model year bike. A sohc 82 is different than a sohc 79-F. The 78-E and 79-F would have the same but all other years will be a bit different. 81 and 82 sohc would be the same but the 80 model is different from all others.