We need to know what year the S10 is, it matters.
The ECM on a 1992 S10 Blazer is located below the glove box.
The ecm module is located behind the passenger side kick panel. I don't know of an ecm relay.
under the dash
The ECM on a 1998 Pontiac Transport with the 3.4 V6 engine is located on the passenger side. It is behind the glove box.
hei ignition or edi ignition
Under the dash in the far right corner
The ECM unit for a 95 S-10 Blazer is located under the hood on pass. side.. Right in the open.
It is located behind the passenger side kick panel.
With a signal from the ecm it powers up the fuel pump.
Inside the dashboard, to the right of the glove box.
Behind the passenger side kick panel.
The ECM on a 2000 S10 ZR2 is located under the hood. It is on the top of the passenger side inner fender.