1992 silverado off-road 4x4 5.7 TBI The old pump worked except for the float. Once I changed pumps there is no power to the pump. Hooked up the old pump and it won't turn over either. Fuse is good but there's no power there either. Prior to installing the new pump there were no issues with the truck. New fuel level gauge on the pump assembly works just fine.
To me it would seem there was a sensor tripped in the electrical system.

 

maybe you should check the continuity of the power wire from the fuse to the connector at the tank....you have power at one end and nothing at the other end...to me that says wiring issue.

 

Performed continuity checks today on power/grey wire from the fuel pump relay to the pump connector, the new pump which is mounted in the tank, the entire bus bar on both sides of the fuseable links, and the fuel pump module. No power out of the mod. unless the grey and orange terminals are jumped--then I have power to the pump. The relaymodule switch was replaced and still no power on the grey power lead. (pump fuse is fine) SO we're down to ECM and PCM in the distributor I guess. Quick and dirty: All leads to the pump connector are functioning// lack power to the fuel pump relay. Ground was to the ground side of the battery (temporarily). For test purposes the old pump was connected to the elec. and worked with the jumper. Been screwing with this for three days and the battery was low--maybe the culprit now.

Comments please!!

 

Let me get this straight. I assume you are using a voltmeter to check for power to the pump? With the battery ground jumped straight to the battery ground terminal, and jumpering the + around the relay to the pump, and you have power? Have you checked for power from the relay with the negative battery wire jumpered to the negative battery?

 

Take the ground lead of you voltmeter to a good ground source, then check for power. Voltmeter reads potential difference, you could be chasing a ground

 

No--tested with a grounded test light

 

Is this problem with both relays?

 

can you post a pic of the wiring diagram

 

Recently received a new fuel pump for a 1992 Silverado K1500. Color code did NOT match the truck harness. Installed it did not work at all. Trouble shot all the associated circuits and in that process unhooked the ECM and re-installed it after checking the circuits in the A/B plug-in harness. Had power at that time and the pump running///backwards. Pulled the tank and found fuel in the return.
This POS was made in china and all but the pump ground were different color than the harness. Pump ground was black with white stripe BUT terminated backward. All 4 wires were wired reverse of normal.
Recommend you check wire terminations before installation and if you have a new one that doesn't work right off, then pull it and check the wiring. In calling the 4 local vendors in my area one of the major distributors had the exact same pump and the same wiring as the new one I'd installed. All of the vendors had different wire colors/code on the pump than is in the MFR's wiring harness. All for between $174. to $190 and all made in China.
Now if you check the internet sales you'll regularly find disclaimers stating build standards that these pumps meet. Horse Hockey!! The shipping boxes state "china, or made in china". I went back to what we all used to do and got one of the old manufacturers that we're all used to; "Made in Mexico". Color code is correct and matches the pump and as pictured is wired correctly.
Before you throw money blindly at various parts in the fuel system check continuity from the fuel relay or just check power with a test light. The Oil Pressure Sensor is a back-up to the relay ONLY. Read-up on the myths. If you have power at the pump harness then suspect the new pump first!! Recommend you visually inspect the pump wiring and compare with your old pump before installation.