FrankS 1978 Special

[Jan_P]

The wiring
If assuming it is wired so for a while yet

There I do Believe
https://thexscafedotcom.wordpress.com/2012/03/14/xs650-78-xs-ese-wiring/

My eyes are not perfect But If I do get it right The Red is from main Fuse and battery
Entering the main Switch

In the off position there is no connection to other wires Br and L
Should be open circuit

The fuse on the brown wire blows as soon as the battery gets connected even with ignition key off (main fuse in)
If it was me I would open that connector Inspect inside there for corrosion Insects and whatnot
Leave it open .. Test if the brown wire fuse no longer fries
Please report the outcome

I would measure Resistance in the now open connector between the 3 pins L / Br / R
Looking for a short in the Off Position Should be Open Circuit no Connection in the Off

Please report back then we Think again

 

[Kevin Werner]

The wiring
If assuming it is wired so for a while yet

There I do Believe
https://thexscafedotcom.wordpress.com/2012/03/14/xs650-78-xs-ese-wiring/

My eyes are not perfect But If I do get it right The Red is from main Fuse and battery
Entering the main Switch

In the off position there is no connection to other wires Br and L
Should be open circuit

The fuse on the brown wire blows as soon as the battery gets connected even with ignition key off (main fuse in)
If it was me I would open that connector Inspect inside there for corrosion Insects and whatnot
Leave it open .. Test if the brown wire fuse no longer fries
Please report the outcome

I would measure Resistance in the now open connector between the 3 pins L / Br / R
Looking for a short in the Off Position Should be Open Circuit no Connection in the Off

Please report back then we Think again


View attachment 334349

View attachment 334348

IIRC the brown should be hot only when the key is in the "ON" position.

 

[650Skull]

Question...............Is the bike a US import or Canadian. Reason i ask is i would like to know if the bike had, or has, a headlight park light

 

[FrankS]

Thank You Sir
So to sum it up
The main fuse no longer fries ..and the only one that does so is the Brown .
I have a wiring I will look on that
I dont believe the Ignition key shall let any power through in the off Position
Frying the Brown
Let me look at the Schematic for 15 minutes or so
Ill get back

Most appreciated!

 

[FrankS]

Question...............Is the bike a US import or Canadian. Reason i ask is i would like to know if the bike had, or has, a headlight park light

USA bike, now in Canada
The ignition switch only seems to have 2 positions: off and on.

 

[650Skull]

Redrew the 78SE Fuse box, (no Fuses), to match loom. Resized the Diagram a bit bigger for a download

Wires are dirty but this looks suspicious

 

[FrankS]

View attachment 334391View attachment 334396

I'll look! Good eye!

 

[Jan_P]

IIRC the brown should be hot only when the key is in the "ON" position.

Yes Sir that is how it has to be According to the Schematic
DC is cut off with the main Switch Red goes all the way from the Battery and Main Fuse
to the switch.( One Branch Only to rectifier )

However Frank Reports that the Brown Fuse Fries regardless off position on Main Switch
But not the Main Fuse
The thought I have here is That in that case
Red somewhere else connects the Red Higher Potential ( Not sure if that is the English Word )
to Brown.
Lower current than 20 A Since main is not frying but higher than 10 since Brow fries

So my thought is to disconnect the Connector at The Main switch Position not affecting
It can be so that there still is a short between Red and Brown .And then a short to ground on brown Downside.
Then think again

 

[FrankS]

Some observations from today:

All fuses removed, battery hooked, up ignition switch on or off, at the disconnected ig switch connector there is continuity to ground of the blue wire leading from the headlight to the fuses.

At disconnected ignition switch connector leading to ig switch -
When the ignition switch is off, there’s no connectivity between the red brown or blue wires.
When the ignition switch is on there is continuity between all three of those wires.

At the ig switch connector in the headlight leading to the fuses, there is no continuity between any of the red brown or blue wires.

Ignition switch off, all fuses are in, when I turn on the ignition switch the fuse to the brown wires blows.

 

[Jan_P]

Some observations from today:

All fuses removed, battery hooked, up ignition switch on or off, at the disconnected ig switch connector there is continuity to ground of the blue wire leading from the headlight to the fuses.

At disconnected ignition switch connector leading to ig switch -
When the ignition switch is off, there’s no connectivity between the red brown or blue wires.
When the ignition switch is on there is continuity between all three of those wires.

At the ig switch connector in the headlight leading to the fuses, there is no continuity between any of the red brown or blue wires.

Ignition switch off, all fuses are in, when I turn on the ignition switch the fuse to the brown wires blows.

Got it The Ignition switch seems to operate Switching on Sends Power to the Fuses
a Current larger than the brown fuse can take

I would measure resistance between low side of that brown Fuse No fuse in --and ground
Having that value as reference se how it changes upon coming actions
I Will look at the Schematic

 

[Jim]

Ignition switch off, all fuses are in, when I turn on the ignition switch the fuse to the brown wires blows.

Did you disconnect all the stuff the brown feeds like I suggested earlier?

 

[Jan_P]

Did you disconnect all the stuff the brown feeds like I suggested earlier?

I Agree there some clever Disconnection helps

Edit To the right on the schematic
Is brown to Flasher cancelling and horn and Light checker
Disconnect
Se if the resistance to ground gets higher

 

[Jan_P]

Nope. As I previously said, brown is (switched) power. It comes out of the ignition switch and powers most of the stuff on your bike. Everything circled in red here is powered by the brown wire.

One of the turn signals is powered by a "chocolate" wire. It's a darker brown... almost black. That's not the brown coming out of the fuse box.

**edited to cross out ignition**
View attachment 334212

I see the red Circles. Yes to That --One way to do it but Perhaps the connectors they can need service Inside

And the lowest one there

 

[Jim]

This isn't rocket science guys. When you turn power on, the brown wire fuse blows. That means something the brown feeds has a dead short to ground. So the normal course of action is to start by disconnecting everything fed by that wire. I circled 'em on a diagram a few days back. Once they're all disconnected, turn power on and see if the fuse blows.

If it does blow, it means the brown wire itself is shorted. We'll cross that bride as/if it arrives.
If it does NOT blow, you start hooking things back up, one at a time and see if that component blows the fuse.... then go to the next component and the next...

Honestly, we've got a short somewhere we need to find. Reading the suggestions in this thread you'd think the Space Shuttle just died or something. It's not that complicated guys. It's a short... we can see it and verify it.... now we just gotta start disconnecting shit 'till it goes away.... it's pretty simple.

 

[FrankS]

Did you disconnect all the stuff the brown feeds like I suggested earlier?

Sorry, no. So, all the multi wire connectors?

 

[Jim]

Sorry, no. So, all the multi wire connectors?

Yes, all of 'em.

 

[5twins]

Don't you have a full wiring diagram to follow? Disconnect anything and everything that has a switched brown wire running to it. Personally, I prefer the original B&W diagram with the wire colors just labeled as opposed to that "colored" version.

 

[Jan_P]

Sorry, no. So, all the multi wire connectors?

No not every one In my view We don't know yet if the wiring is
According to the schematic
Just those leading to the Ones Jim has Circled post #177
2 connectors them If you go that route

Jim is going Bottom, Up and I am thinking Top Down
Or disconnect where Jim has Circled

If the 2 connectors is opened we can Rethink
Or If You do as Jim Suggests we can Rethink
Either way we get more info for conclusions.

 

[FrankS]

Thank you for your patience guys! This isn't my forte'. I read your posts, go out and poke around, come in to read more, go back out.

So last time out I disconnected all the connectors with brown wires including the ignition switch. Installed all the fuses and everything was fine. I reconnected the connectors one by one listening for a fuse to blow but nothing happened. However when I turned on the ig switch, the brown wire fuse blew.

I disconnected the ig switch connector and tested those 3 wires running towards the fuses for continuous to ground. I found the blue with yellow stripe wire ran to ground. I found 2 blue with yellow stripe wires in the main loom and they run back to behind the battery, one through a plastic connector.

Getting closer. Please don't give up on me.

 

[jaybar6]

Hi frank, when you turn on the ignition switch does the red oil/brake light come on and is the green neutral light on?