82gs1100gl. Diode issue. Electrical wisdom??

[eddiev]

My "side stand indicator light" and "oil pressure indicator light" function as one light.

In other words:

1) With bike running and side stand down, both lights are on.
2) With bike running and side stand up, both are off.

I had the diode disconnected among most other connectors for a previous problem.

It's possible I connected the diode backwards. Does anyone know the function of this diode and what would be if I did connect it backwards.

Thanks.
Eddie V

[Billy Ricks]

Diodes allow current to run in just one direction. For instance, I installed GSXR gauges on my bike and they only have one idiot light to cover both signals. I had to put a diode in each line before the idiot light to keep from having all the signals work when they are used.

So yes, diodes can be put in backwards.

[eddiev]

Thanks. I understand that. I just can't figure out from the wiring diagram how the diode is functioning in the circuit and if it even applies to these lights. I first thought it functioned to turn the lights off after the engine is started. I can't follow it though.

[Billy Ricks]

Thanks. I understand that. I just can't figure out from the wiring diagram how the diode is functioning in the circuit and if it even applies to these lights. I first thought it functioned to turn the lights off after the engine is started. I can't follow it though.

The diode is in fact part of the circuit that both those things are on. They both send a ground signal to the lights and positive is always present at the idiot lights. You are actually breaking the ground to turn the lights off. The diode is actually in the ground supply for the left turn signal, at least on my bike. With the diode in backwards the ground is being completed allowing feedback into both circuits.

[Wallowgreen]

Hey Eddie,

Here's my 0.02...

Both indicator lights are fed at one end with 12v via either the orange or orange with green tracer, it's the ground side that has all the fancy stuff.

The grounds from both lights are on when the oil pressure switch is closed i.e. when no oil pressure irrespective of what you do with the side stand, up or down, both lights remain on. That's because of the diode. It allows the ground for the side stand light to be made by the oil pressure switch because it conducts in that direction.

The side stand switch should never light the oil pressure indicator lamp because the diode is reverse biased in that direction and will not allow current to flow, like Billy said, it's a one way gate so to speak.

If you connect it round the wrong way, there should be no harm other than the side stand will light both lights and the oil pressure switch will only control the oil pressure lamp.

You didn't say what happens with the side stand up and the engine off. My bet is only the oil indicator would be on. My money is on you having it connected the wrong way round. I'd turn it round and try again if I were you.

Now, if the diode is shorted, both lights will come on when either the oil pressure switch or the side stand switch is closed. Is that what's happening. If so, you have a duff diode mate. If that's what's happened and it were me, I'd put in a general purpose one. There's nothing special about it. All we have to do is make sure the replacement can handle the current with 12v across it.

[bwringer]

Hey Eddie,

Here's my 0.02...

Both indicator lights are fed at one end with 12v via either the orange or orange with green tracer, it's the ground side that has all the fancy stuff.

The grounds from both lights are on when the oil pressure switch is closed i.e. when no oil pressure irrespective of what you do with the side stand, up or down, both lights remain on. That's because of the diode. It allows the ground for the side stand light to be made by the oil pressure switch because it conducts in that direction.

The side stand switch should never light the oil pressure indicator lamp because the diode is reverse biased in that direction and will not allow current to flow, like Billy said, it's a one way gate so to speak.

If you connect it round the wrong way, there should be no harm other than the side stand will light both lights and the oil pressure switch will only control the oil pressure lamp.

You didn't say what happens with the side stand up and the engine off. My bet is only the oil indicator would be on. My money is on you having it connected the wrong way round. I'd turn it round and try again if I were you.

Now, if the diode is shorted, both lights will come on when either the oil pressure switch or the side stand switch is closed. Is that what's happening. If so, you have a duff diode mate. If that's what's happened and it were me, I'd put in a general purpose one. There's nothing special about it. All we have to do is make sure the replacement can handle the current with 12v across it.

Well stated. And I might add that a new diode costs, what, twelve cents? Fifty cents? Look in your local Radio Shack, in a small stack of drawers behind all the cell phones and iPod accessories. Or visit any electronics shop if there are any left in your area.

[eddiev]

Thanks a bunch guys. It sounds like I must have wired the diode backwards. I forced a low oil indication by grounding the line and I'm pretty sure only the oil light came on. I did this when I first noticed the problem and I'm not positive if only the oil light came on. I was just happy to know I'd have a low oil indication if I needed it.
Hopefully I'll get to play with it this weekend.

Thanks for all the help.
Eddie V

[eddiev]

Update and Fix:

Well, I did install the diode correctly. But it was shorted like you said. Shorted by yours truly. Apparently when I fed the wires into the clear tube I managed to short the leads together. So now all is well.
Thanks for all the help.
Eddie V