Oil Pressure switch..Does this look right?

[oohsam]

Rewired my entire loom. Was just getting together the things I needed off the old loom and i stumbled upon this...Is this right?. Does this just get hooked up to a light. Something tells me that this looks suspicious.

One of the cables comes out of the oil pressure plug on the top of the engine, and then goes up to the dash, where this little resistor thing is, and then the plug into that goes down to the kick stand switch....what the?

It was wrapped in a clear plastic protector thing. It looked like an OEM thing...but who knows.

Cheers.

 

[oohsam]

What the hell.
Just pulled out my wiring diagram. And it looks right. It says here, that a Green and white cable goes from the kickstand to the kickstand warning light, which also goes to the diode.
I looked up diode and it allows current to only flow one way like a valve.
So then it goes from there, through the diode, and out to via Green/yellow cable, to the oil pressure switch, and the oil pressure warning light.

I cant see why the oil pressure and kickstand are related...

 

[posplayr]

What the hell.
Just pulled out my wiring diagram. And it looks right. It says here, that a Green and white cable goes from the kickstand to the kickstand warning light, which also goes to the diode.
I looked up diode and it allows current to only flow one way like a valve.
So then it goes from there, through the diode, and out to via Green/yellow cable, to the oil pressure switch, and the oil pressure warning light.

I cant see why the oil pressure and kickstand are related...

there are a few explainations but would need to look at it , I worked on a safety interlock for both clutch and kickstand. It is possible that oil pressure could be a part of that.

What bike?

 

[mforbes]

What the hell.
Just pulled out my wiring diagram. And it looks right. It says here, that a Green and white cable goes from the kickstand to the kickstand warning light, which also goes to the diode.
I looked up diode and it allows current to only flow one way like a valve.
So then it goes from there, through the diode, and out to via Green/yellow cable, to the oil pressure switch, and the oil pressure warning light.

I cant see why the oil pressure and kickstand are related...

I found the same thing when I took my harness apart. I just wired it in to the new harness. Make sure you wire it the right way.

 

[oohsam]

POSPLAYR.

Its a GS1100G.
Wiring diagram:
http://members.dslextreme.com/users/bikecliff/images/GS1100G_1982_wiring.jpg

I'm not sure if my bike comes witha clutch interlock. Kickstand interlock, maybe. But how is the kickstand related to the oil pressure switch, furthermore, how does the oil pressure switch affect anything wether the kickstand relay is open or closed thus, allowing current through the diode...

This one's really got me.

 

[oohsam]

mforbes. Sounds like a possible solution, however, I'd rather not have stuff wired on the bike that I really dont need or is wasteful.
The other thing is the kickstand switch doesn't get any current flowing through it, so I dont really get that at all....

 

[posplayr]

mforbes. Sounds like a possible solution, however, I'd rather not have stuff wired on the bike that I really dont need or is wasteful.
The other thing is the kickstand switch doesn't get any current flowing through it, so I dont really get that at all....

I found the schematic on BassCliff's website for an 82 GS1100G.

What the diode seems to do is to cause the kickstand light to come on anytime the oil pressure drops. Otherwise the oil pressure light and kick stand lights would operate exactly like you would expect.

I'm guessing it is a safety thing to check the kick stand bulk is not burnt out at startup. Can see any other reason for it.

 

[posplayr]

POSPLAYR.

Its a GS1100G.
Wiring diagram:
http://members.dslextreme.com/users/bikecliff/images/GS1100G_1982_wiring.jpg

I'm not sure if my bike comes witha clutch interlock. Kickstand interlock, maybe. But how is the kickstand related to the oil pressure switch, furthermore, how does the oil pressure switch affect anything wether the kickstand relay is open or closed thus, allowing current through the diode...

This one's really got me.

You would need to draw yourself a little circuit but, when the oil pressure switch is grounded, the diode allows current from he Kick Stand light to ground at the oil pressure switch. So when the oil pressure switch is grounded both lights come on. Nothing to do with kick stand switch.

 

[oohsam]

I've been looking at it also and your explanation seems to make sense. It seems pointless though...

What i was thinking of doing was connecting the neutral light, to the kill switch, to the kickstand switch, so when the following items are met

Kickstand down OR Gearbox in neutral, (and kill switch OFF)
Circuit is closed can start bike,
If Kickstand down and gearbox not in neutral (and kill switch OFF)
Circuit is open cannot sart bike.

I will draw up a circuit diagram for this now and see if it will work.

Also, your advice on bypassing the oil pressure/kickstand system.
If i just want the oil pressure to function on its own, would I just go from the oil pressure switch, to the diode, to the oil pressure light?
If i do that, where does the power come from. I obviously need some sort of power source...

How does the diode in my system affect the oil pressure switch?

 

[posplayr]

I've been looking at it also and your explanation seems to make sense. It seems pointless though...

What i was thinking of doing was connecting the neutral light, to the kill switch, to the kickstand switch, so when the following items are met

Kickstand down OR Gearbox in neutral, (and kill switch OFF)
Circuit is closed can start bike,
If Kickstand down and gearbox not in neutral (and kill switch OFF)
Circuit is open cannot sart bike.

I will draw up a circuit diagram for this now and see if it will work.

Also, your advice on bypassing the oil pressure/kickstand system.
If i just want the oil pressure to function on its own, would I just go from the oil pressure switch, to the diode, to the oil pressure light?
If i do that, where does the power come from. I obviously need some sort of power source...

How does the diode in my system affect the oil pressure switch?

This might give you some ideas on a saftey interlock

http://www.thegsresources.com/_forum/showpost.php?p=1028429&postcount=1

Do a truth table to work out what is going to happen. One column for ach switch (inputs), one column for each output (lights) then just work out each combination.

http://en.wikipedia.org/wiki/Truth_table

With no interlock, the oil light G/W wire just goes to the oil switch
the kick stand light G/W wire just goes to the kickstand switch
leave the diode out.

Diode affects nothing other than to tied both lights to the oil pressure switch. Everything else is the same

 

[oohsam]

Thank you so much. I understand everything, except one slight issue.

If I run the cable that comes out of the oil pressure switch directly to the oil pressure warning light. How does the light come on when oil pressure drops?
Where does the power come from?

The oil pressure light will be grounded, and the oilpressure switch is grounded...but where does the power come from when the oil pressure drops?

 

[mforbes]

Thank you so much. I understand everything, except one slight issue.

If I run the cable that comes out of the oil pressure switch directly to the oil pressure warning light. How does the light come on when oil pressure drops?
Where does the power come from?

The oil pressure light will be grounded, and the oilpressure switch is grounded...but where does the power come from when the oil pressure drops?

The power should be coming from the lighting circuit for the instruments. The oil switch will ground when the pressure is low and the light should be on. The light comes on when you turn the key on with engine not running.

 

[oohsam]

OH!
So the cable from the oil pressure switch is a ground cable, that goes to the (-) on the oil pressure warning light?

 

[Steve]

The oil pressure light will be grounded, and the oilpressure switch is grounded...but where does the power come from when the oil pressure drops?

There is a trick involved there. The oil pressure light is NOT grounded.
At least, not directly.

It is fed power in the instrument panel by the SIGNAL fuse (also powers turn signals, horn and brake lights).
The wire that would ground the light goes through the switch on the engine before it gets to ground.

.

 

[mforbes]

OH!
So the cable from the oil pressure switch is a ground cable, that goes to the (-) on the oil pressure warning light?

If you are looking at the color chart, its hard to tell that. I looked in my service manual and yes it goes to ground when the switch closes at low pressure. As Steve posted, as I was looking at the manual, he is correct. Power is supplied by the light circuit. A pretty good wiring diagram is on bikecliffs site. http://members.dslextreme.com/users/bikecliff/ Look at the diagram for the GS1100. Not the color ones. It shows all the wiring. The Oil pressure switch is toward the bottom right and listed as OP.

 

[posplayr]

OH!
So the cable from the oil pressure switch is a ground cable, that goes to the (-) on the oil pressure warning light?

Yes both the oil switch and kick stand switch are doing low side control of the lights.

The lights are powered but without a ground have no current going through them. Low side control is a safe way to control a load as nothing gets shorted out, which could happen if you were carring power around on a live wire.

 

[oohsam]

!!! Awesome !!!
yes I understand now how it works. This is brilliant. Everything just clicked.
Thanks guys!

 

[posplayr]

There is a trick involved there. The oil pressure light is NOT grounded.
At least, not directly.

It is fed power in the instrument panel by the SIGNAL fuse (also powers turn signals, horn and brake lights).
The wire that would ground the light goes through the switch on the engine before it gets to ground.

.

I think you are saying the same thing? The oil light is grounded through the oil peressure switch to the engine; right?

 

[oohsam]

From what I understood. The oil pressure switch is grounded only when oil pressure drops. How this works I have no idea...but it works.

That cable comes out of the oil pressure switch, goes into the (-) on the warning light, The light has power from the ignition, as well as the other lights, and the ground only becomes active when the oil pressure is low, hence the light comes on.

 

[mforbes]

From what I understood. The oil pressure switch is grounded only when oil pressure drops. How this works I have no idea...but it works.

That cable comes out of the oil pressure switch, goes into the (-) on the warning light, The light has power from the ignition, as well as the other lights, and the ground only becomes active when the oil pressure is low, hence the light comes on.

Inside the switch is a contact that is closed when pressure is low, like when you just turn the key on (engine not running). Thus it makes a ground for the circuit to complete it and the light comes on. Once the engine is started and oil pressure goes up, the oil pressure switch opens and breaks contact with the ground, so no power flows through the light bulb.