XS500 Strange electrical behavior

[minus150]

I was in the process of jetting a set of Mikunu vm32s when I noticed a drop in idle speed each time I slowed to a stop. Initially I suspected a fuel related issue, but found it happens each time the front or rear brake is applied. I started to poke around and noticed more strange electrical behavior:

- I think this is actually normal and not relevant: the flasher relay clicks when the key is turned to 2nd position (where 1st position is off)
- Not relevant: flicking the flasher relay unit will cause the lights to flash when the flash switch is toggled on
- FIXED (the bulb's ground and hot were both plugged to ground): when the flash switch is toggled on, the flashers are solid except for the right front. The bulb in this position is good
- FIXED (caused by undercharged battery/operating without running motor): when either side of flashers are on, they will flash once each time the brake is applied (stop light illuminated)
- FIXED (the brake lining indicator and oil pressure warning bulbs were switched): when the ignition is in 3rd position, the brake lining indicator lights and no flashers will light at all

I have a multi meter but no idea where to start. The manual says solid flashers indicate an unsatisfactory ground. Anyone have any pointers?

 

[toglhot]

Remove the harnes,s throw it in the bin and make another.

 

[minus150]

Total replacement may be the right move, it would be my first time taking that on. I plan to spend some more time troubleshooting before I commit to replacement. So far looking at the headlamp bowl and repair manual diagram I see some wire color inconsistencies and a good amount of electrical tape... probably not a good sign.

 

[toglhot]

The original harness on any bike is rubbish! Designing and making your own has a big plus. It'll be be much better, much simple and you'll be more familiar with it.

 

[650Skull]

I was in the process of jetting a set of Mikunu vm32s when I noticed a drop in idle speed each time I slowed to a stop. Initially I suspected a fuel related issue, but found it happens each time the front or rear brake is applied. I started to poke around and noticed more strange electrical behavior:

- the flasher relay clicks when the key is turned to 2nd position (where 1st position is off)
- flicking the flasher relay unit will cause the lights to flash when the flash switch is toggled on
- when the flash switch is toggled on, the flashers are solid except for the right front. The bulb in this position is good
- when the left flashers are on, they will flash once when the brake is applied
- when the ignition is in 3rd position, the brake lining indicator lights and no flashers will light at all

I have a multi meter but no idea where to start. The manual says solid flashers indicate an unsatisfactory ground. Anyone have any pointers?

If you throw away the harness before diagnosing the problem all you might be doing is spending money and the problem may still be there.

There area lot of small parts, (gauges, ignition switch, left ans right bar switches, taillight/Numberplate light, stator/reg/rect,) with their own harnesses that clip onto the harness where the problem could be.

If it was me, i would do a full continuity test of the bike harness/loom to pin point where the problem is and then decide if the harness can be repaired or buy a new one. The repair could be as simple as replacing a coupling or bullet connectors or/and cleaning/repairing wiring in the bar switches.

I recommend continuity testing because that doesn't require power in the loom/harness to trouble shoot, if you do have a short running power through the loom while testing could make it worse or worst case scenario would be a fire.

Don't know your capabilities............. here is a link on how to continuity test.
https://www.xs650.com/threads/continuity-testing-made-easy.49917/

 

[minus150]

I read through your continuity testing write up, good stuff! My capabilities are limited but I'm starting to get a feel for it. I did make some progress today, I found that the right front flasher positive and ground wires were both connected to ground. I righted that and now get all flashers to light when toggled, however solidly. The left side will blink verrryyy slowly sometimes.

I have been testing voltage with main switch turned on - hope I haven't been causing more damage. Tested with the meter's positive lead on the battery and the negative lead on various grounds. Voltage does drop when the brake is applied, about 0.1V.

 

[Team Junk]

Funny, I was going to suggest looking at your grounds but wasn't expecting that. Did it clear up your ignition problem ?
Your flasher my be toast from being miswired. Stock flasher bulbs right ?

I agree, don't rip out the stock harness. Check for voltage drop at the coils would be my first move.

 

[jetmechmarty]

The flasher stops flashing due undervoltage. It's also old. Mine don't flash on the battery. Sometimes, when I decelerated, the flashing stops when the brake lights come on. I replaced the connector and pins from the stator. That helped. Corrosion in an old harness is a hindrance. If you're not up on proper crimping, splicing and equipped with the proper tools, a new harness could prove problematic.

 

[minus150]

Unfortunately righting the miswired flasher ground didn't resolve anything other than its corresponding bulb now lights up solid when that side is toggled. The other problems persist. The one where applying the brake causes solid flashers to flash once cracks me up a little at least. The ignition issues remain with the flasher relay unplugged so I don't think I can't point a finger there yet. I am using stock incandescent bulbs on all lighting systems. I did come across low voltage preventing flashers from working, battery voltage is on the low side after me fussing with it yesterday. If that were the only issue I'd charge it up and call it a day.

More discovery, the horn is not working and continuity at the handlebar by the LH bar switches tests erratic. Based on some other electrical threads on the board looks my bar ground is bad.

 

[toglhot]

Bin the harness, start again.

 

[650Skull]

Do you have a wiring diagram for your XS500??



Some pics of my bike when i did a full restore on a second hand replacement loom............switches look like this after 30-40 years..........

 

[minus150]

I have been working off of the diagram in my XS500 manual and I am becoming pretty familiar with it. Today I ran some continuity tests on handlebar switches and flasher/dash lighting and didn't find any obvious culprits. I do have some bad speedo/tach bulbs that I need to find a replacement source for. They are the 12V 3.4W variety. My condenser looks pretty tired. I have a replacement for it but my gut says I should hold off on installing the new one until I figure out where my problem is.

I noticed what might be a discrepancy between my bike's main switch and the manual's main switch diagram. I have 3 positions total, OFF, 1, and 2. The diagram says there are 4 total, and I may just be reading it wrong, but the two bottom settings in the diagram look like they would do the same thing? Either I have a non-stock switch or I am reading the diagram wrong.

Also a multi meter noob question: messing around I was finding continuity between headlamp ground and various hot leads (like a dash illumination bulb socket). At first this felt like I had found something to fix, but really I think this should be expected, since I am essentially closing the circuit with my meter leads?

Can anyone walk me through how I can verify my handlebars and thereby handlebar switches are grounded probably? Is this as simple as checking continuity with one lead on the bars, and one on the engine or negative battery terminal?

@650Skull looks like your horn button is disconnected in that image

 

[650Skull]

My bike is an Oceania model, they came out with a Pass switch that would flash the headlight on high-beam when you hit that switch.

Euro and Oceania model XS650's had 4 wires from the ignition switch. The extra was for a park light in the headlight, that could be the same as on the XS500.

Any chance you could take pics and post up the diagram?

This is from the 74TXA 650 assembly manual. May be similar in some things. The 74TX/75XS 650 Dash would swap into the TX/XS500, (and vise versa), up till and including the 75 XS500's The 500's had an oil light where the 650 had a brake fail light

 

[bosco659]

The original harness on any bike is rubbish! Designing and making your own has a big plus. It'll be be much better, much simple and you'll be more familiar with it.

No everyone has the skills to build their own harness. My stock harness still works flawlessly. Should be able to troubleshoot the existing wiring unless it’s been hacked up by someone.

 

[minus150]

I don't have a headlamp diagram equivalent to the one you do. It's all laid out on the same diagram, split down the middle with a divider. There is a section on the flasher circuit. I'm not sure what is meant by "pilot light".

 

[650Skull]

Pilot lights will be the flashing lights, (maybe not in your case), on the dash. High beam light, (blue), neutral, (green),

for some reason your wiring diagram wont open up.

 

[minus150]

Try reloading the page. I noticed my images were crooked so I fixed them and reuploaded.

 

[toglhot]

No everyone has the skills to build their own harness. My stock harness still works flawlessly. Should be able to troubleshoot the existing wiring unless it’s been hacked up by someone.

How do you suppose those that can build harnesses learned the skill?

 

[650Skull]

How do you suppose those that can build harnesses learned the skill?

Personally i post from the point of view, (unless the poster has specifically stated his level of competence and desires and/or he has plenty of money, or how much money he is prepared to spend), that we are here to mend and learn and start my involvement from the point of view.

Why spend money when it can be fixed. By fixing it, or diagnosing, to find a problem, the knowledge gained is worth more than money spent. If it works out it is more problematic to fix it than replace then the knowledge learned is not wasted.

My case specifically was i had no experience with harness's, (even with my experience as a pipe fitter reading engineering plans and building house's, and house plans and sorting the trusses and building the roof to roof plans especially), I had a lot of trouble relating a bike wiring harness Diagram to the harness on the bike.............My learning was to continuity test the whole harness, dismantle and clean all switches, (they were the easy part as they are more mechanical than electrical), couplings and connectors, clean and test between every connection then go back and test after joining every connector till i was testing from one end of a circuit to the other. Slowly as i done this i could understand and read the diagrams.

So yea i walk before i can run and walk others unless they are running first.

 

[toglhot]

Personally i post from the point of view, (unless the poster has specifically stated his level of competence and desires and/or he has plenty of money, or how much money he is prepared to spend), that we are here to mend and learn and start my involvement from the point of view.

Why spend money when it can be fixed. By fixing it, or diagnosing, to find a problem, the knowledge gained is worth more than money spent. If it works out it is more problematic to fix it than replace then the knowledge learned is not wasted.

My case specifically was i had no experience with harness's, (even with my experience as a pipe fitter reading engineering plans and building house's, and house plans and sorting the trusses and building the roof to roof plans especially), I had a lot of trouble relating a bike wiring harness Diagram to the harness on the bike.............My learning was to continuity test the whole harness, dismantle and clean all switches, (they were the easy part as they are more mechanical than electrical), couplings and connectors, clean and test between every connection then go back and test after joining every connector till i was testing from one end of a circuit to the other. Slowly as i done this i could understand and read the diagrams.

So yea i walk before i can run and walk others unless they are running first.

So, why are you telling me this?