Author Topic: Oil pressure  (Read 741 times)

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Offline M_Stone76?

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Oil pressure
« on: July 30, 2023, 05:18:34 PM »
76’ cb750 k

I will make this short and simple

Do I need an oil pressure light if I have an analog oil pressure gauge.
The two tell the pressure so I’m thinking I only need the guage.

The reason why, is my switch is acting up and I’d rather just have the guage.

Opinions?

Online newday777

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Re: Oil pressure
« Reply #1 on: July 30, 2023, 05:54:09 PM »
Can you get by with just the guage, yes, but, if you choose only a pressure guage, I would highly recommend that you mount it up by the speedo to keep an eye on it more often rather than down at the gallery plug location.
You will need to use 1/4" tubing to bring it up to the speedo area.
Stu
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My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
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Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
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New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
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Offline M_Stone76?

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Re: Oil pressure
« Reply #2 on: August 02, 2023, 06:37:22 PM »
Ok,

On another issue. I have an after market indicator light “array” that sits on my handle bar.
I was trying to wire up the oil light.
Checked alll the connections and stuff to make sure everything was working but no light on the array
Weird thing was, when I looked the light would turn off when the switch was grounded.
That’s the opposite of normal.
Could it be a bad/clogged switch?
The oil gallery is completely empty.

Offline HondaMan

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Re: Oil pressure
« Reply #3 on: August 02, 2023, 08:54:31 PM »
Ok,

On another issue. I have an after market indicator light “array” that sits on my handle bar.
I was trying to wire up the oil light.
Checked alll the connections and stuff to make sure everything was working but no light on the array
Weird thing was, when I looked the light would turn off when the switch was grounded.
That’s the opposite of normal.
Could it be a bad/clogged switch?
The oil gallery is completely empty.


The Oil PSI switch is closed (ON) when there is no pressure (i.e., pressure is less than 6 PSI). So, the normal circuit would be to have power going to the light, then the other side of the light goes to the PSI switch.

BUT...if your new light display is LED lights, they will not work with this type of switch. It does not have gold contacts inside, which is what the LED types need because of their low current requirements. One way to 'work around' this is to add another part: a relay with gold contacts that is connected to the Oil PSI switch and +12 volts Ignition power, and the ON contacts of the relay then connected between power and the LED, with the other side of the LED connected to Ground.

LEDs are like that...
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

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Offline Tracksnblades1

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Re: Oil pressure
« Reply #4 on: August 03, 2023, 10:31:51 AM »
76’ cb750 k

I will make this short and simple

Do I need an oil pressure light if I have an analog oil pressure gauge.
The two tell the pressure so I’m thinking I only need the guage.

The reason why, is my switch is acting up and I’d rather just have the guage.

Opinions?

I would keep the oil light…. Redundancies won’t hurt and the light will catch your eye when you’re less than attentive and in lower light levels….. They don’t call them idiot lights for nothing…it’s hard to maintain constant gauge observation with people texting and driving…😳
Age Quod Agis

Offline M_Stone76?

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Re: Oil pressure
« Reply #5 on: August 03, 2023, 11:52:47 AM »
Ok, this is great info. Thanks all

I will try and get a oil light for the “dash”
all in all the switch cannot provide enough power to the LED ?
Is there a better switch I can get / can I get a small red halogen ?

Offline Tracksnblades1

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Re: Oil pressure
« Reply #6 on: August 03, 2023, 12:45:19 PM »
Ok, this is great info. Thanks all

I will try and get a oil light for the “dash”
all in all the switch cannot provide enough power to the LED ?
Is there a better switch I can get / can I get a small red halogen ?

I think Hondaman inference was, LED lights are polarity sensitive. Hook them up backwards they don’t work.
He also mentioned using a relay. Relays can be used to efficiently reverse a normally open, normally closed, or both when properly wired depending on your application. I believe the near negligible current draw of the led is not at issue. The gold contacts are being recommended for reliable operation because of the led’s  very low current draw. He uses the example of the normally closed (oil light on) with no engine oil pressure circuit to emphasize the circuit ground providing switch is not adequate for reliable led light operation..
« Last Edit: August 03, 2023, 12:47:46 PM by Tracksnblades1 »
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Offline Don R

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Re: Oil pressure
« Reply #7 on: August 03, 2023, 07:33:45 PM »
 The contacts are oil soaked and a tiny load can't burn through to work right. On a stock Goldwing they add a light bulb to the circuit to help the switch work. Some guys just hide an extra bulb somewhere.
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