Newbie electrical questions

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big_ang

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I just picked up a 1979 XS650 Special. This is my first bike, and I don't even have a license. This is my first post, so please be gentle on me...

I want to get it together and running, but need a bit of help.

What is missing:
xs650 1.jpg


Where do these connect:
I know the blue, black, and yellow go to my tail light, but I have no clue about the rest.
xs650 2.jpg


The missing fuse was blown and a thick piece of wire was put in, what circuit is the short in:
xs650 3.png


Thanks,
Angelo
1998 Jeep Cherokee - 2dr, 4.0, Auto, 231 4x4
1980 MGB - 3.4V6, T5 transmission, Ford 8.8 posi.
1989 Dodge Daytona Shelby - t-tops, 5 speed, 2.2 intercooled turbo
 
A little help. What's missing...turn signal flasher. The green, dark brown and black if those are the colors are for your rear turn signals, not sure about the red.
 
Looks like that purple wire and the red wire are something the previous owner added. Follow the wires to their source and tell us what that looks like. Might be some sort of accessory.

Here is the fuse panel picture you were looking for.
 

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Does the front and rear signal only connect at the one location? For example, the front right and rear right both connect to the brown?
I assume the black is ground. Do I connect a wire from the ground to the case of the signal?

I traced the purple and red wire and they go to the Suzuki signal lights mounted on the front of the frame. There is only a black wire (with 2 connections) in the headlight bucket that is not connected. I purchased stock signal lights that I'll mount on the headlight, but I don't know where to connect the wires. I can run wires from the inside the headlight bucket and splice into the rear green and brown.

I think I have a short somewhere. I connected the battery, and put a 20A fuse in the "main", but nothing happened. No headlight, signals, brake light, nothing... The fuse didn't pop. Is 20A the correct fuse?

If I don't have a flasher installed, will that cause my lack of lights?
 
You could connect the signals from one location but there was a green/brown in the headlight bucket for the fronts from the factory. The Yamaha turn signals have a hollow threaded stud that they use to mount the signals. The wire coming out of the middle is the hot and would get connected to the green or brown. Green is your right signal,brown left. They then used a ring terminal that went over the stud with the black wire for your ground.

Your bike should have a safety relay under the right side cover near the battery. This relay won't allow the lights to come on until the bike is running. The signals need the flasher to work.

http://www.yamahasportsplaza.com/oemparts/a/yam/50041bd8f8700209bc785e1e/flasher-light
 
In the headlight bucket there are two dark green wires. One goes to the turn sugnal, one goes to the headlight low beam. I helped a fellow with his bike and he had the wires hooked wrong. When he turned the headlight on the turn signal lit instead of the headlight.
On both of the pics showing the fuse boxes, I would replace both with inline fuse holders for the new blade type fuses. Those old glass fuses are a PITA to work with. The clips that hold the fuse get weak, the weak connection creates heat that weakens the clip. After a few years the clips get so weak they break. The fuses often burn out down in the end caps. The fuse gets hot enough under use that it can melt the solder out of the end caps and the fuse is bad with out being blown.
As Grinder said the flasher is what's missing.
The extra wires for the extras signals can be removed if you are using the stock signals. I doubt your PM (Previous Moron) removed the stock wires in the headlight bucket.
Yes, the safety relay does control the headlight. It uses power straight from the alternator to tell when the engine starts and is running to disable the starter and turn the lights on. That way the starter and ignition get all the power the battery has with the extra drain of the headlight to insure easy starts.
Leo
 
I replaced the fuses with modern blade type and connected everything the way it should be.

When I put the key in and put it in run, the neutral light and tail light come on. When I press the start button it just clicks. The headlight or signals don't come on. The horn and tail light work. How can I test the starter?
How do I bypass the part that stops the headlight/signals from coming on when not running?
I wanted to get this sorted out before I move onto the fuel system/carbs.

Posted via Mobile
 
Your bike should have a Safety Relay on the right side. It has 6 wires.......2 red/whites, yellow,black, red/yellow and blue/black. To test the headlight, connect the red/yellow to the blue/black.

When the start button just gives a click, it likely means your battery is discharged or its dead. Low battery voltage also prevents the signals from working. Bench charge the battery at 1/10 of the amp/hr rating for about 10 to 12 hours, and see how that works for you.
 
Thanks for the tip, the headlight works both hi and low. The battery is brand new and fully charged, but the bike will still just click (one click) when the start button is pressed. I think the click comes from the starter solenoid.

Posted via Mobile
 
big_ang said:
Thanks for the tip, the headlight works both hi and low. The battery is brand new and fully charged, but the bike will still just click (one click) when the start button is pressed. I think the click comes from the starter solenoid.

Posted via Mobile
Click to expand...

Could be corroded cable connection down at the starter motor itself. You should remove the 2 large connections at the solenoid, and at the starter motor, and clean them up. If not bad connections, the starter motor can be removed to the bench, and tested to see if it will spin.

Starter solenoid could be bad.....................there's the old trick of shorting across the 2 large lugs with a screw driver as a test.
 
RG's tips are good ones.
Getting the cable off the starter is not easy. The stud on the starter is pointed right at the frame. You can't get the nut off. Before I did much with that I would try a few tests first. As RG said jump the two big cables, does the starter spin the engine? If so it is either the starter relay or connections to it.
The starter circuit isn't to complex. Power comes from the battery through various switches to the starter relay on the red/white wire. If the relay clicks then you have power, might want to check voltage on the red/white wire just to be sure.
The blue/white wire on the relar goes up to the start button where when pushed it grounds the circuit and trips the relay to send power from the battery through the relay to the starter.
The start button grounds the blue/white wire to the switch housing, the switch housing grounds to the bars. The bars get grounded one of two ways. On my 75 the ground path for the bars was a wire from the bottom of one riser bolts around to one of the upper tree clamp bolts, to the stem through the gearings to the frame. Not the best way but works.
The other way was a black wire from the left side switch housing down into the headlight bucket and plugs into the harness ground.
A weak ground path from the start button can cause your problem. As can a weak voltage on the red/white wire. Not enough power to hold the relay more than a click.
Not a very likely prospect but one none the less.
As Rg said more apt to be bad connections on the cables.
I have an extra car battery I use for testing. Hook jumper cables to my spare battery. clamp the ground to the bike, a foot peg mount is handy. Put a long 1/4 or 3/8 bolt in the positive. A screwdriver works too. Now from under the bike peel the rubber cover back on the cable, you may find a lot of corrosion under the rubber, touch the bolt to the stud the cable is on, Does this spin the starter? If so try the same at the relay end of the cable. If it spins good here then the problem is as described earlier and is in the relay or other wires.
Leo
 
I took the starter motor out and, to my surprise, the oil came out! Anyways, I'm learning and I needed to do an oil change anyway.
I took the starter motor apart and cleaned it all up, now it works perfect. The head of one of the long bolts is stripped, so I won't be able to take it apart again unless I can find one of those bolts.

So now my issue is that I only have spark on the left side. I have power to both wires on the coils. What should I look for or test? Swap coils? Condenser? The points look good.

Thanks,
Angelo
 
The 79 has points. One set for ezach cylinder. Power flows to the coils on a red/white wire. From the coils it goes to the points and condersers.
As the engine turns the points open and close. When closed current flows through the coil primary side. This builds a large magnetic feild in the coil. When the points open this magnetic feild collapses. As the feild collapses a very large current is created in the secondary side of the coil. This current is what jumps the gap of the plug to spark.
With no spark on one side, my guess is the points for that cylinder are 1 dirty, 2 gapped wrong. Maybe the wire between the coil and points is damaged.
With the wire from the coil to the points unplugged test for continuity when the points are closed and when they are open. Also check from the wire to ground when the points are open.
Right side is the upper set of points, left is the lower.
I might suggest following the points adjustment procedure in you repair manual.
Leo
 
Oh, it could be a bad plug or plug wire. To test just test the plug that won't spark on the side that does.
To test the plug wire swap the one from the non firing side to the firing side.
Leo
 
I got it sparking on both cylinders now. I narrowed it down to the points. I adjusted them, and now it works great.

I'm trying to remove the Sump filter, but the plate is getting stuck on the kick stand. I'm not sure what to do now...

Posted via Mobile
 
The sump plate will come out. Takes a bit of wiggling, angling. Sometimes that left frame rail is pushed in a bit, perhaps the the PO kick started a lot with the bike on the side stand.
I have taken a big chunk O hardwood and a maul and pushed that frame back out a smidge.
Out of many XSs I have only had to do that once. So work on the angle, wiggle some more first.
By the way it seems you are doing very well, you ask sharp questions, get good answers, figure out the problem, and report back that you have done so, How rare is THAT?

Back away from the bike and shoot some pics? We like to see what you are working on.
 
Drop the right side of the sump plate down while pushing it backwards.
Do not force it! Like gggGary said it will come with some finagling.
Or you can remove the kickstand and do a grease zert mod to it while it is off.


@gggGary. Very rare!
 
I'll try to post some pics when I get a chance, I'm at work and will be going away tomorrow (July 1st is a national holiday in Canada and I'm going up north for the long weekend). I got the bike as-is for $200. It sat in a collapsed shed for 4-5 years and the previous owner was going scrap it along with 4-5 other bikes. It was a divorce situation, the house was sold, and he had clear the place in only a few days as the house was sold. The other bikes were not saved...

The engine was seized, the tank was full of rust but not connected (hopefully no gas sat in the carbs), and the shed had collapsed on it, so lots of damage/weather exposure/mice - it was in pretty bad shape.

Now that I think about it, it must have been on the side stand during the collapse which bent the tab. I remember trying to use the side stand, but it seemed like it was 3" too short. I'll try to bend it back.

So far I had to buy new levers, mirrors, battery, plugs, the bolts for the levers, the spring for the brake lever, air filters, right bar switch (start button was missing), grips, bottom brake fluid cap, and fuel and vac lines.
I found a used seat, tank, chain guard, signals, gauge pods, rear fender with tail light, and front fender from somebody local that did a bobber build. I didn't like the 1981 fender or tail light and seat, so I got another used rear fender and round "standard" tail light from a 1977 and another used seat.
I wanted to keep it stock and have about $800 in it now.
 
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