Wondering where the oil pressure sending unit is on a 1992 Chevy S-10 Blazer . 4x4 , 4.3 Vortec . Automatic w/ac .

Is it on the driver or passenger side , and is it next to the exhaust manifold ?

Problem :

Oil pressure reads "0" for about 5 minutes after cold start . Then pops up to normal level . On warm start , it reads 40psi , but does not change at all with RPMs After the rig has been running for a bit , the guage reads properly . I did just change the oil , but I dont think its related because I did some electrical work under the hood at the same time , and the engine doesnt sound like its lacking oil when the gause says "0" . Also noticed that the oil level goes up on the dip stick just after shutting off the engine , indicating that the oil is draining back down into the pan from , the top end .

 

Located to the right of the distributer at the back of the engine.