bad oil pressure sender?

[brian257]

I have a vans oil pressure gauge and sender that is reading about 10 PSI with the engine not running. Probably a bad sender, but does anyone know what the resistance on the sender should be at zero so I can check mine before I order a new one?

[Joe]

I measured 242 ohms on my Van's Aircraft p/n IE 411K oil pressure sender before I installed it some years ago. It's nominally 240 to 33 ohms.

[brian257]

Thanks. Are you saying that is is supposed to be from 233-240 ohms at 0 PSI or are you saying that it is supposed to read 240 ohms at 0 PSI and 33 ohms at whatever the high end of the pressure range is?

[Joe]

Originally Posted by brian257

... Are you saying that is is supposed to be from 233-240 ohms at 0 PSI or are you saying that it is supposed to read 240 ohms at 0 PSI and 33 ohms at whatever the high end of the pressure range is?

The latter: 240 ohms at 0 PSI. At the upper limit of the rated pressure the resistance decreases to 33 ohms.

Here's a group of pressure senders (not necessarily for an RV) and it will confirm that.

N.B. This explains why an "open" or disconnected sender produces a pegged gauge.

[brian257]

Many thanks.