The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

BR3W CITY · 06-18-2014, 07:10 PM

Pop a different relay in, just to be sure. You can swap that back out, takes 20 seconds.

Then I'd look at the external ground if you have one. After those two easy steps, its pulling the pump out. Are you using the ECM trigger for the fuel pump, or a hotwire of switched +12v?

iirc on the relay its
30- 12v constant
85- ground
87- power to pump
86- fuel pump relay control

If you try to start it, what happens? Is there any change in voltage on the power wire?

06-18-2014, 07:10 PM	#2
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: New in tank fuel pump not working Pop a different relay in, just to be sure. You can swap that back out, takes 20 seconds. Then I'd look at the external ground if you have one. After those two easy steps, its pulling the pump out. Are you using the ECM trigger for the fuel pump, or a hotwire of switched +12v? iirc on the relay its 30- 12v constant 85- ground 87- power to pump 86- fuel pump relay control If you try to start it, what happens? Is there any change in voltage on the power wire? __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD