Oil Gauge Problem_Need Help!

javcamac

New member
Hi,
I recently change the oil pressure gauge from oil line to oil sender...but I can not put it work...
I need help from you guys maybe some picture of how is.
I place one cable direct from the sender and one from the ignition original red cable...but isn't work...I think that I miss something...

thanks in advance for your help...
 

I forgot...is a CJ7 1981 with a 360 engine...
The gauge is a crown make...and have three things:
1. S
2. G
3. I
I suppose that S = sender, I = Ignition, G = Grown...but near to S have a positive symbol (+) so I´m confuse...


Thanks
 
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I would hook up the "S' to the sending unit switch, "G" to ground and "I" to ignition positive. I'm not sure why there would be that "I" terminal.
 
Also I verify with wire tester (I use to know if there a 12V current, the light goes on when detect 12V), but when I connect as you mention, nothing happen and when I touch with the tester the sender cable the idle move.
How can I connect this gauge.
 

Personally I'd scrap that gauge and sender and install a mechanical gauge..
 
What happens if you momentarily short the sending unit circuit to ground while the the other circuits are still attached to their respective terminals. Does the gauge move to the highest point?. Do this test no more than 2 seconds.If the needle doesnt move, it's a bad unit.
 
I do...and the needle does not move.
That's mean that the sender unit is damage or the gauge?
How can I know?

Thanks for your help.
 
Last edited:

Just for clarification. You have the gauge hooked up as follows; I= key on ignition 12V , S= sending unit circuit, G= ground. While the ignition key is on and you momentarily grounded the "S" circuit, no movement on the gauge needle= bad gauge.
 
I'm afraid that I damage the gauge when I try to connect it. well I will buy a new one.
Because initially the needle move when I did what you mention, but without the knowledge and trying after trying may burn the gauge.
But this us a newbe things...so new gauge and I let you know.

Thanks for your support on thus matter.
 
Now I'm very disappoint with myself. This gauge is a pain in the...
I buy a new one and install as it.
But the needle doesn't move.
But when I verify with the 12v tester and I touch the sender cable the needle move up to 20.
Ok my question is...I need another connection to the sender unit or is just one cable.
Now the configuration is:
S = one cable from the sender unit.
I = one cable from the ignition 12v (positive).
G = one cable from the ground.

Thanks...
 

Your making progress. That 12v test lamp just verified that the circuit is complete up to the sending unit connector.The reason it only went up to 20 psi is due to the added resistance in the circuit from the bulb of the test lamp. This suggest that the sending unt is bad.
 
Well I change the sender unit and guess what...the needle doesn't move...but when I turn the key to start position the needle move up to 60...and when I start the engine the needle drop down.
By the way, I connect the mechanical gauge and it's work perfect so the oil is there and the pump is functional.
Finally I don't know why the sender unit and the gauge doesn't work.
If any one have another idea let me know.
Thanks for all the support...
 

Sounds like there's a short to voltage on the sending unit circuit. Trace the wiring and see if there's a pinched or rubbed through sending unit wire.
 
QUICK- CHECK TROUBLE LOCATOR
NO INDICATION AT FAR RIGHT
1. No current to ignition terminal because of
broken or disconnected lead.
2. Grounded wire between sender and
receiver.
3. Receiver not grounded.
4. Sender defective.
EXCESSIVE POINTER FLUCTUATION
1. Loose wire connections.
2. Defective sender
LOW READING AT ALL TIMES
1. Wire to sender broken.
2. Sender not properly grounded.
3. Defective sender.
INDICATES IN ACCURATELY
1. Incorrect sender.
2. Low voltage at receiver terminals.
3. Defective sender.
POINTER FLUCTUATES WHEN LIGHTS ARE
TURNED ON
1. Engine not properly grounded.
 

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like mentioned above, there is no substitute for a manual oil guage, oil there, you'll have a reading.. those idiot lights, and idiot guages are only as good as the wire, sending unit, guage, bulb.. if you can fit it in, use the manual.. you'll be much happier camper..
 
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