Where is OIL Sending Unit on 1994 buick roadmaster

On your engine most likely close to the oil filter . Have a close look around where the oil filter attaches to the engine.

Simple answer, Yes.
I've had a few vehicles where the sending unit was the cause of a leak.

Hope this helps.

Has anyone tested the new temp unit to make sure it's functioning properly? Or is their possibly a mechanical thermostat in it that's hung and needs to be replaced?

On this website you find fuse box diagram and description for Buick Roadmaster (1994)

Buick Roadmaster 1994 fuse box diagram CARKNOWLEDGE

Hi,

This is at the very rear of the engine block on the top in the middle.

Thanks

Jason

check the ignition coil

Fuel Pump RELAY & FUSE CHECKED & DO you Have POWER "TO" Fuel Pump ? ALSO OIL Sending Unit Supplys the GROUND To Fuel Pump , This is A Saftey FEATURE that Shuts Down Fuel If ENGINE Looses OIL PRESSURE . And If This OIL Sending Unit or also Called (OIL PRESSURE SENSOR) << If It FAILS it WILL Cause What Seems Like A Fue Pump Problem But Is Rally Just The Sensor that is BAD. HOPE this Sheds Light on Your Problem !

Attached is pic - It is on top at the rear of the engine

More than likely (and we will hope) it is the oil sending unit. In comparison it is a very cheap and quick fix to replacing the oil pump. Auto Zone has a pretty good componet location section that has tips for replacement if you cant find the sending unit or the oil pump. Try that first it may save you a lot of work.

First check your oil level if it is full take the oil sending unit out and install a pressure gauge to check you oil pressure.Compare your readings to the correct specs for that vehicle.If the pressure is good and the plug that connects to the sending unit has one wire only,do as follows.Take the plug loose from the sending unit,turn the key on and take a paper clip or other item and ground the wire to a good engine ground.If the light illuminates while it is grounded,the circuit and the light itself are good.Do not do this test if there is more than one wire going to the plug!!!I You could just replace the sending unit if you dont wont to test everything..The sending unit is cheap...Good Luck...