It gauges and distributes the power required to get the correct reading from your oil gauge display.
You have a ground from the oil sender unit to the gauge. This is how you check a gauge. ground out the wire at the sender and it pegs out the gauge.
You tap in off the stock oil pressure sender with a T fitting.
My oil pressure gauge is dropping to o and the oil was just changed and is full. What could cause this
There is a open on the sender side of the circuit. Ground the sender wire and if it goes to low then it is the sender if not then the circuit is open.
Sender unit defective sender unit disconnected wiring problem dash to sender rear dash connector problem defective guage
Called an "oil pressure sender", it's most usually close to the oil filter.
There are a variety of reasons from a bad sender or gauge to low oil level to worn bearings. Check the sender first as it's the easiest.
You would need a gauge that taps into where sender goes on block.
There are two different answers here: Older cars - an actual oil line from the engine came into the passenger compartment and was attached to a gauge that read "actual" oil pressure in the engine, so it was actual pressure that made the gauge go up and down. Newer cars - a special unit, called a "sender", is mounted on the engine to monitor engine oil pressure. This "sender" will allow more voltage to go through itself the more oil pressure it monitors. The less pressure it monitors the less voltage. The gauge goes up and down depending on the amount of voltage the "sender" is sending to the gauge.
Sounds like a wiring or sender unit problem. Ground wire at sender unit, see if it stays steady. If it still jumps around, wiring/gauge problem. If it stays steady, sender unit should be replaced. Good idea to do an oil pressure test as well.
Chevrolet had a problem with it's combination sender/switch units used on the 350ci (5.7L) TBI engines in full-size trucks and cars between 1990 and 2000. The sender becomes inoperable due to a loose wire inside the sender itself and makes the gauge erratic. The fix is to replace the sender/switch.
You dont want to feel OR hear the symtoms. If you think you have a bad pump unscrew the oil sender and screw in a pressure gauge.