Fuel pump power


Asked by Jun 06, 2017 at 10:59 PM about the 1995 GMC Sierra 1500 C1500 SLE Extended Cab LB

Question type: Maintenance & Repair

Good evening, I am seeking advice about my truck.
I changed the oil sending unit and now I have to
hardwire my fuel pump to the battery. It takes a lil
time for my truck to start. The relay is new. Does
anyone know what it could possibly be?

5 Answers


Was fuel pump coming on before you swapped oil pressure switch. If not. Check the ground on frame. Might just need to clean up the ground location. Was other switch leaking


Yes it was. It was cranking with no problem.


I am losing oil from around that area. This was the reason why I changed it.


Before hard wiring. Recheck connection on oil pressure switch. That has to energize before fuel pump will come on. With switch on. Orange wire on. Oil pressure switch should have power and the grey should have power. 12 volts on both. The Orange wire on sending unit is powered by ecm b fuse under the hood junction block. If no power on grey wire coming from oil pressure switch. Engine will not start. If you do have 12 volts on grey check your fuel pump relay.

1 of 1 people found this helpful.

I'll check but I did replace the relay with a new one

Your Answer

Sierra 1500

Looking for a Used Sierra 1500 in your area?

CarGurus has 12,112 nationwide Sierra 1500 listings starting at $1,775.

Postal Code:

GMC Sierra 1500 Experts

  • #1
  • #2
    John Saffrahn
  • #3
    Glenn Clingenpeel
View All

Related Models For Sale

Used Ford F-150
509 Great Deals out of 10,018 listings starting at $3,490
Used Dodge Ram 1500
51 Great Deals out of 486 listings starting at $2,495
Used Toyota Tacoma
33 Great Deals out of 1,357 listings starting at $6,900
Used Chevrolet Tahoe
4 Great Deals out of 912 listings starting at $8,500
Used GMC Yukon
3 Great Deals out of 1,117 listings starting at $6,950
Used Chevrolet Camaro
1,075 listings starting at $12,995
Used Jeep Grand Cherokee
146 Great Deals out of 3,993 listings starting at $2,400

Used Cars For Sale

2018 GMC Sierra 1500 For Sale
5 Great Deals out of 9,027 listings starting at $3,570
2017 GMC Sierra 1500 For Sale
10 Great Deals out of 787 listings starting at $1,800
2016 GMC Sierra 1500 For Sale
12 Great Deals out of 575 listings starting at $21,495
2015 GMC Sierra 1500 For Sale
39 Great Deals out of 638 listings starting at $19,944
2014 GMC Sierra 1500 For Sale
30 Great Deals out of 360 listings starting at $16,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.