The Oil Sending Unit on a 1988, 89, and 90 model Silverado is behind the driver side manifold. It is right above the oil filter. It is a canister that is bolted to a piece of tubing that leads to the motor.
Yes, it's in the fuel tank.
Need to know engine size.
on mine, I had to drop the gas tank.
Bad temperature sending unit? Bad gauge?
It is inside of the fuel tank and can be removed from the top of the tank.
If you tell me the engine size, Then I'll tell you were it is.
It is inside of the fuel tank attached to the fuel pump sending unit.
In back of the engine, on top, drivers side, next to the distributor.
It is screewed into the top of the engine right behind the distributor. It is very hard to get to.
It is in the drivers side head by the front spark plug,
A tan/white wire goes from the sending unit to the fuel gauge typically on a (example) 1985 Chevrolet Silverado 305 tbi.