Newbee Electrical Questions…

LikeyMeYommy

XS650 Enthusiast
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Just bought my first bike yesterday… 79 CS650S. Runs but wiring is giving me some problems. Previous owner tried replace disintegrating
fuse box. It’s a total hack job. Tube fuses often fall out of electrical taped in-line housings (uhgg!). Splices all over the place and every wire is red! Thinking about rewiring everything.
QUESTION 1: Spent a bit searching without success. Any good threads with “best strategies” for tackling this?

Also, When the bike is running starter still engages if I push button. I am also having headlight issues (or not turning on at all, low nor hi beam). One time I saw my Hi Beam indicator (blue light) turn on with nothing coming out of the headlight itself. And if I’m being completely honest, I don’t know where the headlight ON/OFF switch is. Wiring diagram seems to show there is one… Searched the forum, sounds like maybe a bad safety relay.
QUESTION 2: What say the experts? Best way to test safety relay?

Brake warning light is intermittently on then goes off, and the repeats. I have no idea why this goes on and off all the time. FYI… rear brake light shines bright when rear brake lever is pressed.
QUESTION 3: Why does this light keep going on and off?

Also, successfully performed the “Grinding Starter Fix” this morning. 2 Wheel Workshop has some very well done videos on YouTube. Bike starts up instantaneously now whereas reeeallly struggled to start up prior to fix. Thanks 2WheelWorkshop and thanks in advance XS650 peeps!

-Steve
 
Welcome!

That's a lot to begin with. The "correct answer" is going to depend primarily on your ability, experience and access to electrical tools and supplies. Sounds like a candidate for a complete rewire if there are several hacked splices throughout the harness.
Some pics of questionable areas may help find better answers.

A stock XS650SF does not have a switch for the headlight: it's always on when running
 
79_XS650SF&2F.PNG
 
hey Likey, Welcome to the xs world of pain and pleasure.

A 79 Doesn't have a on/off light switch. Headlight automatically come on when the engine engages.

I think you hit the button nect to the X when you posted the bike you have......Not many CX's on here that's why i suggest you take a lot of pics of the bike and the wiring. Joking about the CX' part but not the pics

Sounds like it could be up for a total rewire or buy a new loom. They aren't expensive and depending on the condition of your loom it could cave you a pile of heart ache and angst.

Obviously you have some skills having fixed the Bendix gear. Do your self a favor and ask questions before buying any thing, we know the best places and sometimes the cheapest is what you get and other times you can save a heap of money and get good parts.

That starter still engaging means the safety relay isn't working. There is a starter cut off relay on the right side of the bike near the starter solenoid, A bronze looking lump about 2" long and 1" high.

The PO may have has disconnected it. It is unusual for them to crap out but that is a possibility.

Pics and lots of them, Some closer and others not so close.
 
Your bike has two relays in this circuit. One turns on the headlight, the other deactivates the starter. Both use a wire off the alternator... 6-5v of charging current goes to both... one turns the light on, one turns the starter (the safety relay) off. Both are very reliable. I'll give you much higher odds the charging system isn't working over both relays failing at the same time.

Edit: or the hack job wiring isn't letting the charging current get to the relays.
 
Thanks Guys. Really appreciate your feedback and passion for the XS. Very inspiring!

Moving #1 up to college this weekend but lots of pics coming!!!

Any suggestions on reliable parts for a complete rewire? I think I can handle it. Pretty capable/dangerous with a volt meter (ha!). I was wondering if there were any good posts/directions for how to tackle this as I’m more concerned with efficiently disassembling and rerouting than I am with the actual electrical stuff.

I’ll check for voltage at those relays. RE charging system… is this from the 2 brushes on the stator housing???

Thanks for wiring diagram. What are the Reserve Lighting and Light Checker functions?
 
I’ll check for voltage at those relays. RE charging system… is this from the 2 brushes on the stator housing???
There is a yellow wire in the sub-harness coming from the stator: that's the one that powers safety relay
 
how to tackle this as I’m more concerned with efficiently disassembling and rerouting than I am with the actual electrical stuff.
Lots of options; basically remove seat and tank, remove headlight from its bucket, remove battery, then start at one end and unplug and remove as you go. Reverse order to assemble. There are cable routing guides in the manuals, but take pictures too (before) for reference
 
Just perform the simple charging test - start the bike and measure battery voltage at idle and revved to about 3K RPMs. At idle you should see around 12, revved up that should climb to the low to mid 14's. If you get no change when you rev it, you have charging issues.
 
The only thing that appears hacked in those photos is the fuse-box itself. That can be replaced with an OEM style plug-n-play from Mike's, or you can wire-in a modern one with some modification to the wiring. What does the other end of that mess look like (white block connector)?

Not enough damage shown yet to replace harness
 
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OK. Have some additional info. Voltage meter at battery @1200 RPM = 12.7V. Voltage @ 3100 RPM = 14.2V. Does not seem to go over 14.2 at higher RPM. I think this is good. Seems to be charging.

FYI... starter IS disabled when motor is running. It just barks at me a bit when starting (even though I did the "grinding starter" fix) but no longer obnoxious).

Niether headlight beam (Low or Hi) works...
 
1 and 2 are the safety relay, controls headlight and starter over run. it's connector just to the right of it. One of the relays failing is not rare. There's some jumper tests/work arounds.
 
1 and 2 are the safety relay, controls headlight and starter over run. it's connector just to the right of it. One of the relays failing is not rare. There's some jumper tests/work arounds.
OK. I'm going to start by checking if I have 12V at the headlight Low Beam. I know headlight should be on when engine starts. Is it supposed to be on when key is in ON position but engine is not started?
 
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