hey everybody. i have a '92 s10 blazer vin w. replaced the fuel pump over a month ago, and everything runs fine. yesterday my neighbor comes over and tells me the vehicle is making a noise. i listened and noticed right away the fuel pump was running.the blazerhad been off for hours, so i was a little confused. first i disconnected the relay, and it stayed on, i don't know if this is normal. if i take out the ecmb fuse it turns off. could this be a relay problem? maybe a short somewhere? any feedback is appreciated, it will run fine but this is an unwanted nuisance.

 

You definitely have a short if it still runs even after pulling the relay. I believe that the relay is the last thing in the main power lead to the pump.

 

any ideas on where to look for such a short? i have the haynes manual but this is very vague. also how could i test for it?

 

I'm afraid you are going to just have to follow the wires. I went through this on my Dad's '94 K2500. Just had to pull the main power wire out of the harness and inspect. Ended up not being able to get it out at one point so we just replaced it. But that was a short to ground that resulted in the fuse blowing. Sounds to me like you have a short to power so more than one wire is involved.

Wiring problems are a pain to deal with.

 

while looking at the haynes wiring diagram, i noticed that there is a fuel pump/oil pressure switch in line with the pump. i am not sure what the function of this item is, could this be the culprit? i have noticed that my oil pressure is unusually high when it runs, but after some time(15 minutes or more)it starts to level out. could this switch have something to do with my issue? and where might i locate it?