Oil pressure gauge

[Jonny]

My oil pressure gauge is at zero when off and full when grounded but measures 1/4th when key is on without starting the car. Rallye gauges and new can style sending unit. Thoughts? Thx

 

[Rapidfire]

What does the gauge read with the engine running at idle?

 

[fasjac]

How’s the amp/volt gauge looking when the key is on? I’ve seen that gauge make weird things happen when not working right. Just a thought.

 

[Robert Franke]

Assuming what you ment was 0 key off and quarter and pegged when sender wire grounded with key on.. I would do a resistance ck on the sender wire..and the ground ckt to the guage

 

[Robert Franke]

Before you pull th trigger on spare parts..agree with what are the other guages doing?

 

[volunteer]

Most factory electronic gauges with only L or H markings were comparable to 40 - 60 - 80 - 100. With engine cold, start it then notice needle position at Cold fast-idle, warm fast-idle (above 2000) and then warm curb idle (for lowest value). If not happy, suggest install good manual gauge (although a nuisance to remove sending unit by dist.) Do similar test and compare values. Most of the large 'can-style' sending units have a max. pressure value stamped on hex - ie: 80, 100 - but this feature no effect on static gauge reading (engine off and key on).