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Discussion Starter #1
Have a 2000 Ultra Classic with 50k on the clock and the oil light occasionally comes on. But, the oil pressure gauge indicates great oil pressure--usually around 32 psi or just below at 3000 engine rpm. At an idle it drops like it always does, but the light does not usually come on. Regardless of engine speed, though, this light occasionally comes on. Recently, during a heavy rain the light came on and stayed on. If it wasn't for the pressure gauge telling me everything was still good, I was about to pull over. I'm thinking I've got a simple short at the sending unit and the rain helped to make the connection. Rode again recently and the light stayed off. Not sure if I should be concerned, especially since I've got a working gauge. Thoughts?
 

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I have an 02 Ultra that does the same thing when it gets wet. I haven't found where the problem is but I trust the pressure guage knowing that the oil level is right. If you find where the problem is, please pass the info along.
 

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I also have a 2000, it happened to me twice, 1st time it was a rub on the wire on the frame, from the pressure switch on the lower right side if the motor, 2 time the switch went out.
 

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With 50K on the bike,have you ever had the cam chain tensioners checked?
If not I would do so.
If you know the tensioners are good,the gauge could be defective or a wiring problem.
 

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Discussion Starter #5
Thanks everyone. @ RG50: cam chain tensioners are gone, went with gear to gear system. Thinking it's a wiring problem too. Will dig into it further.
 

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Bill, if there is ever a doubt about oil pressure, never depend on anything electrical to tell you the truth.

I would put a mechanical gauge on is and see what you really have for pressure.
 

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Discussion Starter #7
Bill, if there is ever a doubt about oil pressure, never depend on anything electrical to tell you the truth.

I would put a mechanical gauge on is and see what you really have for pressure.
Hmm, you make a good point, but I'm fairly confident that the gauge on the fairing (which is reading a solid 32 psi) is giving me an accurate reading rather than the idiot light. If the fairing gauge was shorting it would read either pegged one way or the other, not an actual flow from low to high as engine rpm increases--which it has done faithfully since the bike was new. And it wouldn't show good pressure as the light comes on. If pressure wasn't there, I'd expect, at the very least, a fluctuating reading. Thank you for the thought, though.
 

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I guess that is why they call it an idiot light!
 

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Discussion Starter #9
I guess that is why they call it an idiot light!
In the old'en days, back when Fred Flintstone was ogling Barney Rubbles wife, we used to add gauges on our bikes, cars, lawn mowers... Just to make sure we knew what was really happening in that confounded internal combustion machine--besides a light that would tell you when it was too late.
 

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Hmm, you make a good point, but I'm fairly confident that the gauge on the fairing (which is reading a solid 32 psi) is giving me an accurate reading rather than the idiot light. If the fairing gauge was shorting it would read either pegged one way or the other, not an actual flow from low to high as engine rpm increases--which it has done faithfully since the bike was new. And it wouldn't show good pressure as the light comes on. If pressure wasn't there, I'd expect, at the very least, a fluctuating reading. Thank you for the thought, though.
Please remember that the gauge in the Fairing is electrical..... They are prone to mess up too.

I would screw a mechanical gauge and hose into it to get a "True" oil pressure reading.. ;)
 

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Discussion Starter #11
Update on that oil pressure light flickering on my Ultra...
Looked in the big book and they even cover this.
If Oil pressure gauge is reading normal but oil light is on.
1) pull sending unit plug off to expose terminals.
2) with engine off, check with an ohm meter. One probe on sending unit terminal the other against crankcase. reading should be no resistance.
3) check with engine running at about 2,000 rpm, reading should be infinite resistance -- no continuity.
4) any other reading, replace the sending unit.

In other words--duhhhh-- if the gauge shows oil pressure and the light is on, replace the sending unit.
In reality, just taking off the plug was apparently enough to dislodge whatever grime was giving me a flicker as the light never came on coming to work today.
 

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Out of curiosity, do the gauge and light get their information from the one sending unit, or does each one have its own sender?
They share the same sending unit.
 

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Discussion Starter #15
I asked the question because if both get the same input, it strikes me as odd that only one would indicate a problem.
I'm thinking -- as I have been all along -- that it's a simple bad connection from the sending unit to the warning light. I'm thinking I just need to clean up that one terminal. Will give that a try and report.
 

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Have a 2000 Ultra Classic with 50k on the clock and the oil light occasionally comes on. But, the oil pressure gauge indicates great oil pressure--usually around 32 psi or just below at 3000 engine rpm. At an idle it drops like it always does, but the light does not usually come on. Regardless of engine speed, though, this light occasionally comes on. Recently, during a heavy rain the light came on and stayed on. If it wasn't for the pressure gauge telling me everything was still good, I was about to pull over. I'm thinking I've got a simple short at the sending unit and the rain helped to make the connection. Rode again recently and the light stayed off. Not sure if I should be concerned, especially since I've got a working gauge. Thoughts?
The rain and even a dewy morning will give you continuity if you have some dirt/dust in the wrong spot.
Wipe the engine and near the wiring and it might fix your problem.

Years ago, I had the same problem with my car (hot rod days.)
Usually replaced the plugs every fall but Holley quit making the plugs so I left the old plugs in the engine.
Usually when changing out the plugs, the new plugs wouldn't have any dust on them but because I didn't replace, when spring came around, the dewy mornings wouldn't let the car start. Let it sit and the sun came out, then the dew was gone and the car would start.
I had the high performance clips on the plugs but they let condensation make an electrical path from the plug tip, down the outside of the plug to ground.
Cleaned the path, it cleared the problem.
 

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Discussion Starter #17
The rain and even a dewy morning will give you continuity if you have some dirt/dust in the wrong spot.
Wipe the engine and near the wiring and it might fix your problem.

Years ago, I had the same problem with my car (hot rod days.)
Usually replaced the plugs every fall but Holley quit making the plugs so I left the old plugs in the engine.
Usually when changing out the plugs, the new plugs wouldn't have any dust on them but because I didn't replace, when spring came around, the dewy mornings wouldn't let the car start. Let it sit and the sun came out, then the dew was gone and the car would start.
I had the high performance clips on the plugs but they let condensation make an electrical path from the plug tip, down the outside of the plug to ground.
Cleaned the path, it cleared the problem.
Great advise, that's what I've been thinking all along. Giving that --cleaning-- a try right now.
 
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