I recently purchased a 1979 Corvette which originally had an L-82 engine. It was replace with an 1982 engine that is no longer any good. I am in the process of installing a new 350/290 hp GM crate engine. This is my first Corvette and I have several wiring issues to resolve. First, it appears that the water temperature sending unit is on the right (passenger side) rear side of the head. The wire going to the sending unit has 2 wires in the connector. A blue wire and black wire. The sending unit only has only 1 flat metal pin on the end. Which wire (blue or black) should be connected to the sending unit or should the sending unit have 2 flat pins on the end?

Second, their is a sending unit switch located in the block just above the oil filter that has a 1 pin wire running to it. What is this for? My 79 has an oil temperature gauge in place of where the clock is usually located in earlier model Corvettes. Is this the oil temperature sending unit?

Third, There is a canister type sending unit located in the top of the block just behind the intake manifold with 1 wire running to it. Is this the oil pressure sending unit.

Finally, the 350/290 block does not have a hole in the block on the right rear side to attach the spark plug heat shield to. The bumped out area like the front and other side is there, but no hole. Do you know if a hole can be drilled and tapped at this location.

Thanks for any help you can give.

 

On my 78 the sending unit for the oil pressure is above the oil filter. The water temp sender is located in the left cyl head. The port on the back of the block behind the intake is plugged. It is an L-82.

 

Thanks for the info. Does your temperature sending unit have 1 or 2 wires running to it?

 

The temperature sending unit is the one down by the oil filter, the oil pressure is the one located by the distributor.

The 79-80 cars used a single wire temperature sending unit. I'll have to check later on a schematic, but it sounds like the two wire connection you are looking at was for a car with HD. Cooling which had a switch mounted on the block on the passenger side. It was a two wire switch that controlled the axillary cooling fan.

I've got to run out for a while, but when I return I'll pull the schematic if someone else has not answered you question about the temp wires.

Willcox

 

Thanks, I just looked at the old block and there is some type of barrel-type sending unit in the middle of the block just up from the oil pan on the passenger side. It has 1 round pin sticking out and it doesn't look like it had anything connected to it. Any help you can provide from your schematics will be greatly appreciated.

 

Page 8A-52 of the '79 factory shop manual shows the coolant temp. sensor L/S of engine between #1 & #3 spark plugs. Oil pressure sender unit is on rear L/S of engine. Both single wires. Coolant = DRK GRN, & Oil pressure wire is TAN.

 

The blue and black wire connector on the passenger side of the engine goes to the auxiliary cooling fan temperature switch which is on the right rear side of the block.

 

For a '79 this would be true but it appears as though the OP had replaced the engine with a 1982? Maybe the OP could clarify this and is a 1982 L-82 any different from a 1979 L-82?

 

Good question. Unfortunately I am the 4th owner. I have asked the 2nd and 3rd owners and they don't know. The original owner who replaced the original 79 engine with the 82 is unknown. I am kind of on my own to try and figure things out. So far, the info from forum members has been really helpful.