Keeps popping main fuse....

[Bob Wegman]

Yes, I read that. I literally just double checked and my screws are all fine… been thru this whole bike and I keep blowing 20A fuses but intermittently. Everything in the headlight bucket is fine, the grommets are fine. No issues there. I’ve gone through every connector everywhere and nothing is shorting out but I still keep blowing these fuses. Rotor tests out fine….

To save yourself from blowing fuses, replace the fuse with a test light, when the light goes out you have found the short.

 

[GLJ]

Nope. Nothing to do with either of those. Blows just riding, no brakes or signals

Can you ride with out your headlight on?

 

[Grimly]

Check the wiring harness at the steering neck.
It's a common place for wear and tear to cause a short or break, most commonly a short to ground. It's usually the wires you don't see, the ones nearest the metal frame, so a quick inspection reveals nothing.

 

[gggGary]

Go up to a 25 amp fuse? For testing purposes only.
How many watt is that H4 headlight bulb you're using?

 

[kenintn]

Hey Ken, old thread. Dont know if youre stillaround. But you said touch meter probe to hot brush and other to any ground correct and should be no more then 2.25amps??

To confirm, you remove the brown brush lead wire from the brush holder, Set your meter on amps, connect the red lead to the wire you removed , the black lead to the spot where they screw held it to the brush holder.
Simply turn the ignition on and the amp meter should show about 2. 25 Amps if it reads high amps you have a bad rotor
If it checks within that range, then I would look where your wiring harness goes through your headlight can. That rubber O-ring wears out from vibration. . The metal headlight can hole cuts through it and starts cutting into the wiring harness. When you’re checking, it look for signs of arcing around the edge of the hole. Check your wiring harness sheath. Make sure it’s intact.

If you get into a situation, where, as soon as you turn ignition on, it blows the fuse do this. Take a tail, light bulb or a turn. Signal bulb, connect two wires to it, (socket) connect one wire on one side of the fuse clip, the other wire on the other side of the fuse clip, (use alligator clips, )Turn your ignition on, if the light burns bright, you’ve got a short.) With the light burning, bright, start moving wiring harness, shaking it, if it’s in the harness, and your movement interrupts the short, that lights gonna go dim or out. Wherever you were shaking it that’s where it’s at.
These are the two likely places I’ve seen that blows the main views.

Hope this helps. Good luck. Keep us informed for as alway, Inquiring minds want to know.

UK
Kenintn

 

[kenintn]

Hey Ken, old thread. Dont know if youre stillaround. But you said touch meter probe to hot brush and other to any ground correct and should be no more then 2.25amps??

To confirm, you remove the brown brush lead wire from the brush holder, Set your meter on amps, connect the red lead to the wire you removed , the black lead to the spot where they screw held it to the brush holder.
Simply turn the ignition on and the amp meter should show about 2. 25 Amps if it reads high amps you have a bad rotor
If it checks within that range, then I would look where your wiring harness goes through your headlight can. That rubber O-ring wears out from vibration. . The metal headlight can hole cuts through it and starts cutting into the wiring harness. When you’re checking, it look for signs of arcing around the edge of the hole. Check your wiring harness sheath. Make sure it’s intact.

If you get into a situation, where, as soon as you turn ignition on, it blows the fuse do this. Take a tail, light bulb or a turn. Signal bulb, connect two wires to it, (socket) connect one wire on one side of the fuse clip, the other wire on the other side of the fuse clip, (use alligator clips, )Turn your ignition on, if the light burns bright, you’ve got a short.) With the light burning, bright, start moving wiring harness, shaking it, if it’s in the harness, and your movement interrupts the short, that lights gonna go dim or out. Wherever you were shaking it that’s where it’s at.
These are the two likely places I’ve seen that blows the main views.

Hope this helps. Good luck. Keep us informed for as alway, Inquiring minds want to know.

UK
Kenintn

 

[75XSFLORIDA]

55W, so just 4.5A. I don’t think they have lightbulbs doing anything… with the brushes out I get no continuity from ring to engine fin on either ring, so that’s good…everything is charging fine. I’m telling you i have literally gone through every connector on this bike and everything is very solid, no bare wires touching any metal or anything crazy. This is a mystery.

 

[75XSFLORIDA]

To confirm, you remove the brown brush lead wire from the brush holder, Set your meter on amps, connect the red lead to the wire you removed , the black lead to the spot where they screw held it to the brush holder.
Simply turn the ignition on and the amp meter should show about 2. 25 Amps if it reads high amps you have a bad rotor
If it checks within that range, then I would look where your wiring harness goes through your headlight can. That rubber O-ring wears out from vibration. . The metal headlight can hole cuts through it and starts cutting into the wiring harness. When you’re checking, it look for signs of arcing around the edge of the hole. Check your wiring harness sheath. Make sure it’s intact.

If you get into a situation, where, as soon as you turn ignition on, it blows the fuse do this. Take a tail, light bulb or a turn. Signal bulb, connect two wires to it, (socket) connect one wire on one side of the fuse clip, the other wire on the other side of the fuse clip, (use alligator clips, )Turn your ignition on, if the light burns bright, you’ve got a short.) With the light burning, bright, start moving wiring harness, shaking it, if it’s in the harness, and your movement interrupts the short, that lights gonna go dim or out. Wherever you were shaking it that’s where it’s at.
These are the two likely places I’ve seen that blows the main views.

Hope this helps. Good luck. Keep us informed for as alway, Inquiring minds want to know.

UK
Kenintn

Thanks Ken!
So heres the deal. This is a 75 and the only colored brush wires are green and black. As far as it blowing, i can ride for miles and miles and then blows…never blows just with a start, only when riding. Headlight bucket grommets are flawless all rubber new, I’ve literally been thru the bucket over 10 times! All wires are immaculate, nothing exposed. All connections are fully covered and snug and beautiful. Harness sheath is also intact and looks brand new at all points throughout the harness. Rotor slip rings ohm out fine. Bike charges at 3k rmps fine. This is a mystery

 

[75XSFLORIDA]

Ken, on my meter here what would be the appropriate amp setting??

 

[magoo66]

Check the wiring harness at the steering neck.
It's a common place for wear and tear to cause a short or break, most commonly a short to ground. It's usually the wires you don't see, the ones nearest the metal frame, so a quick inspection reveals

Check the wiring harness at the steering neck.
It's a common place for wear and tear to cause a short or break, most commonly a short to ground. It's usually the wires you don't see, the ones nearest the metal frame, so a quick inspection reveals nothing.

Had the blowing of the fuse occurred prior to replacing the on/off switch on the handlebars

Check the wiring harness at the steering neck.
It's a common place for wear and tear to cause a short or break, most commonly a short to ground. It's usually the wires you don't see, the ones nearest the metal frame, so a quick inspection reveals nothing.

Was the bike blowing the fuse prior to installing the new on/off handlebar replacement switch?

 

[75XSFLORIDA]

Had the blowing of the fuse occurred prior to replacing the on/off switch on the handlebars

Was the bike blowing the fuse prior to installing the new on/off handlebar replacement switch?

How did you know I replaced my on/off switch?? And i did that years ago and no, nothing prior to that and nothing after that til now. That was replaced in 2020. Lol

 

[magoo66]

Had the blowing of the fuse occurred prior to replacing the on/off switch on the handlebars

Was the bike blowing the fuse prior to installing the new on/off handlebar replacement switch?

Apologize,asked twice,big thumbs.

 

[magoo66]

I just recall it from one of the posts. I was just curious if it could be faulty or giving a random short.Best wishes locating your problem/s.

 

[650Skull]

Just maybe it is still the same problem. Maybe it's Jim rotor. Have you eliminated that yet

https://www.xs650.com/threads/rewou...rouble-shooting-charging-system.63772/page-29

 

[75XSFLORIDA]

Just maybe it is still the same problem. Maybe it's Jim rotor. Have you eliminated that yet

https://www.xs650.com/threads/rewou...rouble-shooting-charging-system.63772/page-29

Man you’re late! Lol
Jims rotor has been in a storage box for three weeks now so yea man it’s eliminated!

 

[kenintn]

this type problem is hard to find. However you can isolate circuits then bring them back one at a time if you have the patience.
The wiring goes like this. A resd wire comes from the fuse to the headlight can where it then connects to the ignition switch Out of the igi switch come three wires. A Blue, Brown and red/Yellow. Locate the ign ?SW harness in the HL can. Unplug the Blue (instrument lights and the R/Y wires ( Headlight switch power). Ride the bike. If the fuse does not blow it's in one of these circuits. If it does... The brown wire goes to several places. Locate the wires that come from the engine run switch on the h-Bar. This is the ignition circuit. the other wires go to

Ken, on my meter here what would be the appropriate amp setting??

the 2000ua is a 2amp current reading setting but the current will be greater than this value. . Not sure on your meter what “Battery” is for. Read your owners manual and see what it says. Most meters have a separate hole you plug the red lead in and it is for measuring 10 amp or more current.

UK

 

[kenintn]

Locate the wires that come from the engine run switch on the h-Bar. This is the ignition circuit. LEAVE IT PLUGED UP. the other wires go to things like horn turn signals and such. I’d unplug them (keep track (with pics) where they go) and just leave the ignition circuit connected. Then plug one at a time back up , ride it a bit snd see if the fuse blows. When you connect the circuit with the issue it should reveal itself. Note the charging circuit will be disconnected, until you plug it back in so monitor your battery voltage.

UK

 

[75XSFLORIDA]

this type problem is hard to find. However you can isolate circuits then bring them back one at a time if you have the patience.
The wiring goes like this. A resd wire comes from the fuse to the headlight can where it then connects to the ignition switch Out of the igi switch come three wires. A Blue, Brown and red/Yellow. Locate the ign ?SW harness in the HL can. Unplug the Blue (instrument lights and the R/Y wires ( Headlight switch power). Ride the bike. If the fuse does not blow it's in one of these circuits. If it does... The brown wire goes to several places. Locate the wires that come from the engine run switch on the h-Bar. This is the ignition circuit. the other wires go to

the 2000ua is a 2amp current reading setting but the current will be greater than this value. . Not sure on your meter what “Battery” is for. Read your owners manual and see what it says. Most meters have a separate hole you plug the red lead in and it is for measuring 10 amp or more current.

UK

I have a 75….my ig switch is different. I have red wire coming out of mine for a total of FOUR wires.

 

[75XSFLORIDA]

this type problem is hard to find. However you can isolate circuits then bring them back one at a time if you have the patience.
The wiring goes like this. A resd wire comes from the fuse to the headlight can where it then connects to the ignition switch Out of the igi switch come three wires. A Blue, Brown and red/Yellow. Locate the ign ?SW harness in the HL can. Unplug the Blue (instrument lights and the R/Y wires ( Headlight switch power). Ride the bike. If the fuse does not blow it's in one of these circuits. If it does... The brown wire goes to several places. Locate the wires that come from the engine run switch on the h-Bar. This is the ignition circuit. the other wires go to

the 2000ua is a 2amp current reading setting but the current will be greater than this value. . Not sure on your meter what “Battery” is for. Read your owners manual and see what it says. Most meters have a separate hole you plug the red lead in and it is for measuring 10 amp or more current.

UK

So the 2000ua setting on my meter will display what if say for example my reading is 2amps when i do the test. What will meter show? Also battery setting on my meter shows volts, like measuring a car battery so i wouldnt use that.

 

[75XSFLORIDA]

A small error slipped in above:

1µA is 1 millionth of an Amp

1mA is 1 thousandth of an Amp

2000µA ia 2mA or 0.002A

Meters often have a dedicated socket for measuring higher currents above say 1A. The socket will be labelled something like 10A and have a warning saying for 10 seconds maximum. Longer than 10 seconds will heat the meter circuitry up far too much and cause damage.

Yea i dont have that socket. All i have are these settings here so not sure what my meter will read if say for example the measurement showed 2amps on the correct meter.