Odd Oil Change Issue

Guys,
Just had my oil changed in my 355. Mobil 0w40. new filter, etc. Work is being done by quality shop I have used for my Porsche for years. They also do Ferrari.

What has happened is although everything is put back as it was, with the exception of new oil and filter, I am no longer getting an oil pressure reading to the gauge. The temp is showing normal but obviously I am a bit uneasy not seeing the pressure reading. The gauge was fine before the change.

Any thoughts?

Thank you

 

two wires. grounded out the connections. red light is working but the needle refuses to move.

 

also on start up red light comes on and goes off so I assume there is actually pressure just the needle is not reading. Just an uncomfortable feeling not seeing that needle register.

 

all the way down.

 

Thanks everyone. The problem is pointing to the sender. The gauge is fine. We did get a new sender in but true for today it had a broken post so no go. We put a manual pressure gauge in place of the sender and the pressure is fine. I drove the car home without issue. The suspect sender puts the red light out so it too assumes there is pressure. The only issue is the needle hasn't come back. We were able to max the needle by grounding out this wire.

I should have a replacement sender by Tuesday. Easy to swap in. Hopefully his drama is over then.

Thank you all. You guys are great. Weird that the sender fails right after a routine oil change but I suppose it is as good a time as any to fail. I went from 15w40 to 0w40 so maybe this helped push the sender to the cliff.

 

Hello,
So the saga continues. Finally got a new sender unit installed. Same issue as the old sender unit. Red light goes off upon start so there is oil pressure but still no needle movement.

Does anyone have a wiring diagram so I can see how the cable routes? The gauge is not the issue, I don't think, since it can be shorted and the needle made to move. Maybe a resistor problem or feedback from the ECU is not happening.

Thanks