Ok let's see who can help me. 1994 s-10, cpi. Fuel pump will not turn on when i turn the key forward. My first thought was the pump....nope its good. Secondly i chancged the icm, tested bad and put a new one in....nope didnt help anything. Now im thinking the wiring harness for the sending unit. What do you all think? Would I have to buy a whole new sending unit for this?

 

Do you have +12V and ground to the fuel pump? If you have both at the connector to the pump, then there has to be a problem with the pump.

 

Well here's the problem. The pump runs. Usually in the morning it will kick on when I turn the key forward. Other times it will not. I'm going over it again today after work and well see what I find. Bad ground?? wire harness??

 

A bad $5 relay? Its one of the little square black things on the firewall. There is also one for your horn right beside it. You can switch em and see if it works better for you. There is a female pigtail wire hanging around this location that is not connected to anything, you can feed 12v to this to bypass the relay for diagnostic purposes.