# 86.5 VG30 oil pressure guage reads 0



## Deerhurst (Jul 25, 2011)

i have a 1986.5 4x4 hardbody with the VG30. i noticed when i was driving into town yesterday that the oil pressure guage on the dash reads 0. oil level is full ( doesnt burn oil ever ), all fuses are good and the truck sounds as quiet as always and runs as good as ever. the oil light on the dash is also off. 

im going to run out and check the connections to the sensor behind the oil filter. I dont really want to check the regulator under the oil filter for 2 reasons, 1) have no reason to pull the filter off yet as i dont have the oil to do an oil change and 2) i dont know what to look for. and im just speculating on its loction.

any other suggestions you gurus can give me?


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## Deerhurst (Jul 25, 2011)

update: oil pressure warning light does not light up when the key is turned to ON and engine is not running.


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## TheRepairMan (Jun 30, 2009)

It's typically referred to as an Oil Pressure Sending Unit if the truck has an oil pressure gauge, and it looks something like this...










And, if it also has a warning light on it for oil pressure, the light gets turned off and on with an Oil Pressure Switch and it will usually look something like this.










Some vehicles have a Sender/Switch combined into one unit, but just about any of the above are mounted near the oil filter or adapter.

It's fairly easy to test the circuits to see if you can actuate the gauge or turn on the light, but you will have to locate and identify the wires and connectors at the switch and/or sender first.

-Roger


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## smj999smj (Jan 1, 2006)

There should be power at the gray wire to the oil sender with the key "on." If not, check the fuses in the fuse block. The oil pressure gauge is contolled by the dashboard voltage regulator, along with the fuel and coolant gauges. Power goes through a 10A fuse in the fuse block, through a joint connector, then to pin #28 of the cluster harness connector, which will be a white wire with a black stripe and on the corner of the connector. Pin #28 powers the fuel sub gauge as well as the voltage regulator, which in turn powers the fuel, coolant and oil pressure gauges. The ground side of the oil pressure gauge exits via a gray wire at pin #27, which goes to the oil pressure switch. If the fuel and coolant gauges are working correctly, I would check the circuit between the cluster and the switch and the switch, itself. If those are okay, you may have a bad printed circuit on the back of the cluster or oil pressure gauge.


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## Deerhurst (Jul 25, 2011)

i know where the sender is andthe wires seem intact and the connection is dry inside. i do have the dash light, where might i look for the switch? what values am i looking for when testing them? im assuming to test things such as resistance through the device for the sender and the switch to tell of they are working properly.


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## Deerhurst (Jul 25, 2011)

smj999smj said:


> There should be power at the gray wire to the oil sender with the key "on." If not, check the fuses in the fuse block. The oil pressure gauge is contolled by the dashboard voltage regulator, along with the fuel and coolant gauges. Power goes through a 10A fuse in the fuse block, through a joint connector, then to pin #28 of the cluster harness connector, which will be a white wire with a black stripe and on the corner of the connector. Pin #28 powers the fuel sub gauge as well as the voltage regulator, which in turn powers the fuel, coolant and oil pressure gauges. The ground side of the oil pressure gauge exits via a gray wire at pin #27, which goes to the oil pressure switch. If the fuel and coolant gauges are working correctly, I would check the circuit between the cluster and the switch and the switch, itself. If those are okay, you may have a bad printed circuit on the back of the cluster or oil pressure gauge.


fuses are all good, last time a fuse for my dash went out the entire dash did nothing. checked the fuses last night. all other guages work fine. ill go pull outthe trusty shop manual and see if i can pin point those pins mentioned in the wirig schematics.


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## smj999smj (Jan 1, 2006)

Should just be the one switch, Nissan P/N B5070-07G11. Nissan MSRP is $83.90 and look like the top pick above; probably a lot cheaper from Rockauto.com. There's a special tool to remove the switch and it can be a real pain to remove without it. It's sort of a 90 degree crowsfoot with metal clips that snap around the body of the switch. Kent-Moore made the original, but K-D Tools also make ones and probably some other manufacturers.


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## Deerhurst (Jul 25, 2011)

will i be finding the switch over by the oil filter on the truck?


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## smj999smj (Jan 1, 2006)

Yeah, it's in a "fun" place just above and in front of the starter!


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## Deerhurst (Jul 25, 2011)

and i thought the connector on the sensor unit was hard to get to. any specific values i should see when i hit it with a volt meter?


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## smj999smj (Jan 1, 2006)

You should see battery voltage with the sender disconnected; the sender is the ground of the circuit.


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## Deerhurst (Jul 25, 2011)

on the truck side of the connector to the sender i saw 4.19 volts with the ignition ON


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## smj999smj (Jan 1, 2006)

I forgot about the voltage regulator, so that "might" be correct. Connect the circuit to a ground and see if the gauge responds and climbs to "high" or whatever it maxes out at. If it does, replace the oil sender.


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## Deerhurst (Jul 25, 2011)

wel, the gauge maxxed out when the wire was grounded. gonna start looking for the sender unit. thanks for all the help! the sender should be the cause of the oil pressure light staying off when the key is at ON and the truck is not running, oil pressure is then 0, correct?


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