New oil sender fitted still crazy readings

[swimmer27]

Last week my oil pressure reading went to the max 100 so I purchased a new sender and fitted it today, as soon as the ignition is on the gauge reads to the max then as i start her the needle drops to the value you can see in the photo

as the engine warms up and the oil thins then the gauge rises instead of falling!
When you remove the sender wire the gauge falls to zero and when I earth the wire to the chasis it rises to 100 so I presume the gauge is ok.
All my earths are ok as I cleaned these a few months ago when I had issues with my cooling fan so any ideas fellow S owners?

[Jakko]

Hi, I am quite new to the forum, but I had a thought. In the photo the temp gauge looks to be reading quite high if you have only turned the ignition on. In my experience with a 3000M the two gauges are fed from the same power source that reduces the voltage from 12v to an average of around 7.5v to stop fluctuation caused by power differences. The point being that if both gauges are reading high, it points to the Voltage Stabiliser. On my M this was fitted to the back of the dash. No idea about an S. Hope this helps.

[Griffinr]

I think you have the wrong sender, Some work the other way round, high resistance at the opposite end of the scale. I made the same mistake and had to buy another one.

Rob.

[swimmer27]

Jakko said:

Hi, I am quite new to the forum, but I had a thought. In the photo the temp gauge looks to be reading quite high if you have only turned the ignition on. In my experience with a 3000M the two gauges are fed from the same power source that reduces the voltage from 12v to an average of around 7.5v to stop fluctuation caused by power differences. The point being that if both gauges are reading high, it points to the Voltage Stabiliser. On my M this was fitted to the back of the dash. No idea about an S. Hope this helps.

Hi, the engine had been running for 10 minutes so the reading is correct for the temp, when the ignition is turned on from cold the temp gauge stays at the bottom but the oil gauge rises to the top

[swimmer27]

swimmer27 said:

Hi, the engine had been running for 10 minutes so the reading is correct for the temp, when the ignition is turned on from cold the temp gauge stays at the bottom but the oil gauge rises to the top

Thanks Rob I think you are right, oh well that's the risk you take buying from EBay.