94 chevy blazer 350
 

So I've recently replaced my knock sensor and oil pan gasket, starter then oil pressure starts to drop do i replace the oil pressure sensor and it won't start the starter is making a very loud grinding noise when trying to start the check engine light is on I put a paper clip in the obd to see what codes I have I came up with the electronic spark control and fuel relay low voltage I replace the control module and it still doesn't start

I don't know what to do at this point

The fuel relay is under the hood on the firewall, how many miles are on the truck? I know that there was always a issue with low oil pressure in the blazers.. my engine has 10,000 miles on it and the pressure isnt really high and was told by gm alot of it has to do with no zinc being put in oil any more to buy zinc additive every oil change.. loud noise from starter could mean its not engaging when you turn the key so yes i would replace that .. i used one of the high torque starters they are alot smaller and lighter but do the job very well